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From: Thomas Zimmermann <tzimmermann@suse.de>
To: daniel.vetter@ffwll.ch, mpatocka@redhat.com, sam@ravnborg.org,
 geert+renesas@glider.be, bernie@plugable.com, corbet@lwn.net
Cc: dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org,
 linux-doc@vger.kernel.org, Thomas Zimmermann <tzimmermann@suse.de>
Subject: [PATCH] fbdev: Remove udlfb driver
Date: Mon, 30 Nov 2020 13:52:00 +0100
Message-Id: <20201130125200.10416-1-tzimmermann@suse.de>
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Udlfb has been superseded by DRM's udl. The DRM driver is better by
any means and actively maintained. Remove udlfb.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 CREDITS                      |    5 +
 Documentation/fb/index.rst   |    1 -
 Documentation/fb/udlfb.rst   |  162 ---
 MAINTAINERS                  |    9 -
 drivers/video/fbdev/Kconfig  |   17 +-
 drivers/video/fbdev/Makefile |    1 -
 drivers/video/fbdev/udlfb.c  | 1994 ----------------------------------
 7 files changed, 6 insertions(+), 2183 deletions(-)
 delete mode 100644 Documentation/fb/udlfb.rst
 delete mode 100644 drivers/video/fbdev/udlfb.c

diff --git a/CREDITS b/CREDITS
index 748301954ab7..fed3518c4dd8 100644
--- a/CREDITS
+++ b/CREDITS
@@ -3620,6 +3620,11 @@ S: 145 Howard St.
 S: Northborough, MA 01532
 S: USA
 
+N: Bernie Thompson
+E: bernie@plugable.com
+W: http://plugable.com/category/projects/udlfb/
+D: DisplayLink USB 2.0 framebuffer driver
+
 N: Doug Thompson
 E: dougthompson@xmission.com
 D: EDAC
diff --git a/Documentation/fb/index.rst b/Documentation/fb/index.rst
index baf02393d8ee..8136c84328e2 100644
--- a/Documentation/fb/index.rst
+++ b/Documentation/fb/index.rst
@@ -36,7 +36,6 @@ Frame Buffer
     sstfb
     tgafb
     tridentfb
-    udlfb
     uvesafb
     vesafb
     viafb
diff --git a/Documentation/fb/udlfb.rst b/Documentation/fb/udlfb.rst
deleted file mode 100644
index 732b37db3504..000000000000
--- a/Documentation/fb/udlfb.rst
+++ /dev/null
@@ -1,162 +0,0 @@
-==============
-What is udlfb?
-==============
-
-This is a driver for DisplayLink USB 2.0 era graphics chips.
-
-DisplayLink chips provide simple hline/blit operations with some compression,
-pairing that with a hardware framebuffer (16MB) on the other end of the
-USB wire.  That hardware framebuffer is able to drive the VGA, DVI, or HDMI
-monitor with no CPU involvement until a pixel has to change.
-
-The CPU or other local resource does all the rendering; optionally compares the
-result with a local shadow of the remote hardware framebuffer to identify
-the minimal set of pixels that have changed; and compresses and sends those
-pixels line-by-line via USB bulk transfers.
-
-Because of the efficiency of bulk transfers and a protocol on top that
-does not require any acks - the effect is very low latency that
-can support surprisingly high resolutions with good performance for
-non-gaming and non-video applications.
-
-Mode setting, EDID read, etc are other bulk or control transfers. Mode
-setting is very flexible - able to set nearly arbitrary modes from any timing.
-
-Advantages of USB graphics in general:
-
- * Ability to add a nearly arbitrary number of displays to any USB 2.0
-   capable system. On Linux, number of displays is limited by fbdev interface
-   (FB_MAX is currently 32). Of course, all USB devices on the same
-   host controller share the same 480Mbs USB 2.0 interface.
-
-Advantages of supporting DisplayLink chips with kernel framebuffer interface:
-
- * The actual hardware functionality of DisplayLink chips matches nearly
-   one-to-one with the fbdev interface, making the driver quite small and
-   tight relative to the functionality it provides.
- * X servers and other applications can use the standard fbdev interface
-   from user mode to talk to the device, without needing to know anything
-   about USB or DisplayLink's protocol at all. A "displaylink" X driver
-   and a slightly modified "fbdev" X driver are among those that already do.
-
-Disadvantages:
-
- * Fbdev's mmap interface assumes a real hardware framebuffer is mapped.
-   In the case of USB graphics, it is just an allocated (virtual) buffer.
-   Writes need to be detected and encoded into USB bulk transfers by the CPU.
-   Accurate damage/changed area notifications work around this problem.
-   In the future, hopefully fbdev will be enhanced with an small standard
-   interface to allow mmap clients to report damage, for the benefit
-   of virtual or remote framebuffers.
- * Fbdev does not arbitrate client ownership of the framebuffer well.
- * Fbcon assumes the first framebuffer it finds should be consumed for console.
- * It's not clear what the future of fbdev is, given the rise of KMS/DRM.
-
-How to use it?
-==============
-
-Udlfb, when loaded as a module, will match against all USB 2.0 generation
-DisplayLink chips (Alex and Ollie family). It will then attempt to read the EDID
-of the monitor, and set the best common mode between the DisplayLink device
-and the monitor's capabilities.
-
-If the DisplayLink device is successful, it will paint a "green screen" which
-means that from a hardware and fbdev software perspective, everything is good.
-
-At that point, a /dev/fb? interface will be present for user-mode applications
-to open and begin writing to the framebuffer of the DisplayLink device using
-standard fbdev calls.  Note that if mmap() is used, by default the user mode
-application must send down damage notifications to trigger repaints of the
-changed regions.  Alternatively, udlfb can be recompiled with experimental
-defio support enabled, to support a page-fault based detection mechanism
-that can work without explicit notification.
-
-The most common client of udlfb is xf86-video-displaylink or a modified
-xf86-video-fbdev X server. These servers have no real DisplayLink specific
-code. They write to the standard framebuffer interface and rely on udlfb
-to do its thing.  The one extra feature they have is the ability to report
-rectangles from the X DAMAGE protocol extension down to udlfb via udlfb's
-damage interface (which will hopefully be standardized for all virtual
-framebuffers that need damage info). These damage notifications allow
-udlfb to efficiently process the changed pixels.
-
-Module Options
-==============
-
-Special configuration for udlfb is usually unnecessary. There are a few
-options, however.
-
-From the command line, pass options to modprobe
-modprobe udlfb fb_defio=0 console=1 shadow=1
-
-Or modify options on the fly at /sys/module/udlfb/parameters directory via
-sudo nano fb_defio
-change the parameter in place, and save the file.
-
-Unplug/replug USB device to apply with new settings
-
-Or for permanent option, create file like /etc/modprobe.d/udlfb.conf with text
-options udlfb fb_defio=0 console=1 shadow=1
-
-Accepted boolean options:
-
-=============== ================================================================
-fb_defio	Make use of the fb_defio (CONFIG_FB_DEFERRED_IO) kernel
-		module to track changed areas of the framebuffer by page faults.
-		Standard fbdev applications that use mmap but that do not
-		report damage, should be able to work with this enabled.
-		Disable when running with X server that supports reporting
-		changed regions via ioctl, as this method is simpler,
-		more stable, and higher performance.
-		default: fb_defio=1
-
-console		Allow fbcon to attach to udlfb provided framebuffers.
-		Can be disabled if fbcon and other clients
-		(e.g. X with --shared-vt) are in conflict.
-		default: console=1
-
-shadow		Allocate a 2nd framebuffer to shadow what's currently across
-		the USB bus in device memory. If any pixels are unchanged,
-		do not transmit. Spends host memory to save USB transfers.
-		Enabled by default. Only disable on very low memory systems.
-		default: shadow=1
-=============== ================================================================
-
-Sysfs Attributes
-================
-
-Udlfb creates several files in /sys/class/graphics/fb?
-Where ? is the sequential framebuffer id of the particular DisplayLink device
-
-======================== ========================================================
-edid			 If a valid EDID blob is written to this file (typically
-			 by a udev rule), then udlfb will use this EDID as a
-			 backup in case reading the actual EDID of the monitor
-			 attached to the DisplayLink device fails. This is
-			 especially useful for fixed panels, etc. that cannot
-			 communicate their capabilities via EDID. Reading
-			 this file returns the current EDID of the attached
-			 monitor (or last backup value written). This is
-			 useful to get the EDID of the attached monitor,
-			 which can be passed to utilities like parse-edid.
-
-metrics_bytes_rendered	 32-bit count of pixel bytes rendered
-
-metrics_bytes_identical  32-bit count of how many of those bytes were found to be
-			 unchanged, based on a shadow framebuffer check
-
-metrics_bytes_sent	 32-bit count of how many bytes were transferred over
-			 USB to communicate the resulting changed pixels to the
-			 hardware. Includes compression and protocol overhead
-
-metrics_cpu_kcycles_used 32-bit count of CPU cycles used in processing the
-			 above pixels (in thousands of cycles).
-
-metrics_reset		 Write-only. Any write to this file resets all metrics
-			 above to zero.  Note that the 32-bit counters above
-			 roll over very quickly. To get reliable results, design
-			 performance tests to start and finish in a very short
-			 period of time (one minute or less is safe).
-======================== ========================================================
-
-Bernie Thompson <bernie@plugable.com>
diff --git a/MAINTAINERS b/MAINTAINERS
index c5a399541d6a..2b445f87e1ef 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -5178,15 +5178,6 @@ F:	fs/quota/
 F:	include/linux/quota*.h
 F:	include/uapi/linux/quota*.h
 
-DISPLAYLINK USB 2.0 FRAMEBUFFER DRIVER (UDLFB)
-M:	Bernie Thompson <bernie@plugable.com>
-L:	linux-fbdev@vger.kernel.org
-S:	Maintained
-W:	http://plugable.com/category/projects/udlfb/
-F:	Documentation/fb/udlfb.rst
-F:	drivers/video/fbdev/udlfb.c
-F:	include/video/udlfb.h
-
 DISTRIBUTED LOCK MANAGER (DLM)
 M:	Christine Caulfield <ccaulfie@redhat.com>
 M:	David Teigland <teigland@redhat.com>
diff --git a/drivers/video/fbdev/Kconfig b/drivers/video/fbdev/Kconfig
index 4f02db65dede..41189b31c5d6 100644
--- a/drivers/video/fbdev/Kconfig
+++ b/drivers/video/fbdev/Kconfig
@@ -558,7 +558,7 @@ config FB_STI
 	  BIOS routines contained in a ROM chip in HP PA-RISC based machines.
 	  Enabling this option will implement the linux framebuffer device
 	  using calls to the STI BIOS routines for initialisation.
-	
+
 	  If you enable this option, you will get a planar framebuffer device
 	  /dev/fb which will work on the most common HP graphic cards of the
 	  NGLE family, including the artist chips (in the 7xx and Bxxx series),
@@ -1939,21 +1939,6 @@ config FB_SMSCUFX
 	  (USB 3.0) devices.
 	  To compile as a module, choose M here: the module name is smscufx.
 
-config FB_UDL
-	tristate "Displaylink USB Framebuffer support"
-	depends on FB && USB
-	select FB_MODE_HELPERS
-	select FB_SYS_FILLRECT
-	select FB_SYS_COPYAREA
-	select FB_SYS_IMAGEBLIT
-	select FB_SYS_FOPS
-	select FB_DEFERRED_IO
-	help
-	  This is a kernel framebuffer driver for DisplayLink USB devices.
-	  Supports fbdev clients like xf86-video-fbdev, kdrive, fbi, and
-	  mplayer -vo fbdev. Supports all USB 2.0 era DisplayLink devices.
-	  To compile as a module, choose M here: the module name is udlfb.
-
 config FB_IBM_GXT4500
 	tristate "Framebuffer support for IBM GXT4000P/4500P/6000P/6500P adaptors"
 	depends on FB
diff --git a/drivers/video/fbdev/Makefile b/drivers/video/fbdev/Makefile
index 477b9624b703..49b5dd0bef02 100644
--- a/drivers/video/fbdev/Makefile
+++ b/drivers/video/fbdev/Makefile
@@ -106,7 +106,6 @@ obj-$(CONFIG_FB_COBALT)           += cobalt_lcdfb.o
 obj-$(CONFIG_FB_IBM_GXT4500)	  += gxt4500.o
 obj-$(CONFIG_FB_PS3)		  += ps3fb.o
 obj-$(CONFIG_FB_SM501)            += sm501fb.o
-obj-$(CONFIG_FB_UDL)		  += udlfb.o
 obj-$(CONFIG_FB_SMSCUFX)	  += smscufx.o
 obj-$(CONFIG_FB_XILINX)           += xilinxfb.o
 obj-$(CONFIG_FB_SH_MOBILE_LCDC)	  += sh_mobile_lcdcfb.o
diff --git a/drivers/video/fbdev/udlfb.c b/drivers/video/fbdev/udlfb.c
deleted file mode 100644
index f9b3c1cb9530..000000000000
--- a/drivers/video/fbdev/udlfb.c
+++ /dev/null
@@ -1,1994 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * udlfb.c -- Framebuffer driver for DisplayLink USB controller
- *
- * Copyright (C) 2009 Roberto De Ioris <roberto@unbit.it>
- * Copyright (C) 2009 Jaya Kumar <jayakumar.lkml@gmail.com>
- * Copyright (C) 2009 Bernie Thompson <bernie@plugable.com>
- *
- * Layout is based on skeletonfb by James Simmons and Geert Uytterhoeven,
- * usb-skeleton by GregKH.
- *
- * Device-specific portions based on information from Displaylink, with work
- * from Florian Echtler, Henrik Bjerregaard Pedersen, and others.
- */
-
-#include <linux/module.h>
-#include <linux/kernel.h>
-#include <linux/init.h>
-#include <linux/usb.h>
-#include <linux/uaccess.h>
-#include <linux/mm.h>
-#include <linux/fb.h>
-#include <linux/vmalloc.h>
-#include <linux/slab.h>
-#include <linux/delay.h>
-#include <asm/unaligned.h>
-#include <video/udlfb.h>
-#include "edid.h"
-
-static const struct fb_fix_screeninfo dlfb_fix = {
-	.id =           "udlfb",
-	.type =         FB_TYPE_PACKED_PIXELS,
-	.visual =       FB_VISUAL_TRUECOLOR,
-	.xpanstep =     0,
-	.ypanstep =     0,
-	.ywrapstep =    0,
-	.accel =        FB_ACCEL_NONE,
-};
-
-static const u32 udlfb_info_flags = FBINFO_DEFAULT | FBINFO_READS_FAST |
-		FBINFO_VIRTFB |
-		FBINFO_HWACCEL_IMAGEBLIT | FBINFO_HWACCEL_FILLRECT |
-		FBINFO_HWACCEL_COPYAREA | FBINFO_MISC_ALWAYS_SETPAR;
-
-/*
- * There are many DisplayLink-based graphics products, all with unique PIDs.
- * So we match on DisplayLink's VID + Vendor-Defined Interface Class (0xff)
- * We also require a match on SubClass (0x00) and Protocol (0x00),
- * which is compatible with all known USB 2.0 era graphics chips and firmware,
- * but allows DisplayLink to increment those for any future incompatible chips
- */
-static const struct usb_device_id id_table[] = {
-	{.idVendor = 0x17e9,
-	 .bInterfaceClass = 0xff,
-	 .bInterfaceSubClass = 0x00,
-	 .bInterfaceProtocol = 0x00,
-	 .match_flags = USB_DEVICE_ID_MATCH_VENDOR |
-		USB_DEVICE_ID_MATCH_INT_CLASS |
-		USB_DEVICE_ID_MATCH_INT_SUBCLASS |
-		USB_DEVICE_ID_MATCH_INT_PROTOCOL,
-	},
-	{},
-};
-MODULE_DEVICE_TABLE(usb, id_table);
-
-/* module options */
-static bool console = true; /* Allow fbcon to open framebuffer */
-static bool fb_defio = true;  /* Detect mmap writes using page faults */
-static bool shadow = true; /* Optionally disable shadow framebuffer */
-static int pixel_limit; /* Optionally force a pixel resolution limit */
-
-struct dlfb_deferred_free {
-	struct list_head list;
-	void *mem;
-};
-
-static int dlfb_realloc_framebuffer(struct dlfb_data *dlfb, struct fb_info *info, u32 new_len);
-
-/* dlfb keeps a list of urbs for efficient bulk transfers */
-static void dlfb_urb_completion(struct urb *urb);
-static struct urb *dlfb_get_urb(struct dlfb_data *dlfb);
-static int dlfb_submit_urb(struct dlfb_data *dlfb, struct urb * urb, size_t len);
-static int dlfb_alloc_urb_list(struct dlfb_data *dlfb, int count, size_t size);
-static void dlfb_free_urb_list(struct dlfb_data *dlfb);
-
-/*
- * All DisplayLink bulk operations start with 0xAF, followed by specific code
- * All operations are written to buffers which then later get sent to device
- */
-static char *dlfb_set_register(char *buf, u8 reg, u8 val)
-{
-	*buf++ = 0xAF;
-	*buf++ = 0x20;
-	*buf++ = reg;
-	*buf++ = val;
-	return buf;
-}
-
-static char *dlfb_vidreg_lock(char *buf)
-{
-	return dlfb_set_register(buf, 0xFF, 0x00);
-}
-
-static char *dlfb_vidreg_unlock(char *buf)
-{
-	return dlfb_set_register(buf, 0xFF, 0xFF);
-}
-
-/*
- * Map FB_BLANK_* to DisplayLink register
- * DLReg FB_BLANK_*
- * ----- -----------------------------
- *  0x00 FB_BLANK_UNBLANK (0)
- *  0x01 FB_BLANK (1)
- *  0x03 FB_BLANK_VSYNC_SUSPEND (2)
- *  0x05 FB_BLANK_HSYNC_SUSPEND (3)
- *  0x07 FB_BLANK_POWERDOWN (4) Note: requires modeset to come back
- */
-static char *dlfb_blanking(char *buf, int fb_blank)
-{
-	u8 reg;
-
-	switch (fb_blank) {
-	case FB_BLANK_POWERDOWN:
-		reg = 0x07;
-		break;
-	case FB_BLANK_HSYNC_SUSPEND:
-		reg = 0x05;
-		break;
-	case FB_BLANK_VSYNC_SUSPEND:
-		reg = 0x03;
-		break;
-	case FB_BLANK_NORMAL:
-		reg = 0x01;
-		break;
-	default:
-		reg = 0x00;
-	}
-
-	buf = dlfb_set_register(buf, 0x1F, reg);
-
-	return buf;
-}
-
-static char *dlfb_set_color_depth(char *buf, u8 selection)
-{
-	return dlfb_set_register(buf, 0x00, selection);
-}
-
-static char *dlfb_set_base16bpp(char *wrptr, u32 base)
-{
-	/* the base pointer is 16 bits wide, 0x20 is hi byte. */
-	wrptr = dlfb_set_register(wrptr, 0x20, base >> 16);
-	wrptr = dlfb_set_register(wrptr, 0x21, base >> 8);
-	return dlfb_set_register(wrptr, 0x22, base);
-}
-
-/*
- * DisplayLink HW has separate 16bpp and 8bpp framebuffers.
- * In 24bpp modes, the low 323 RGB bits go in the 8bpp framebuffer
- */
-static char *dlfb_set_base8bpp(char *wrptr, u32 base)
-{
-	wrptr = dlfb_set_register(wrptr, 0x26, base >> 16);
-	wrptr = dlfb_set_register(wrptr, 0x27, base >> 8);
-	return dlfb_set_register(wrptr, 0x28, base);
-}
-
-static char *dlfb_set_register_16(char *wrptr, u8 reg, u16 value)
-{
-	wrptr = dlfb_set_register(wrptr, reg, value >> 8);
-	return dlfb_set_register(wrptr, reg+1, value);
-}
-
-/*
- * This is kind of weird because the controller takes some
- * register values in a different byte order than other registers.
- */
-static char *dlfb_set_register_16be(char *wrptr, u8 reg, u16 value)
-{
-	wrptr = dlfb_set_register(wrptr, reg, value);
-	return dlfb_set_register(wrptr, reg+1, value >> 8);
-}
-
-/*
- * LFSR is linear feedback shift register. The reason we have this is
- * because the display controller needs to minimize the clock depth of
- * various counters used in the display path. So this code reverses the
- * provided value into the lfsr16 value by counting backwards to get
- * the value that needs to be set in the hardware comparator to get the
- * same actual count. This makes sense once you read above a couple of
- * times and think about it from a hardware perspective.
- */
-static u16 dlfb_lfsr16(u16 actual_count)
-{
-	u32 lv = 0xFFFF; /* This is the lfsr value that the hw starts with */
-
-	while (actual_count--) {
-		lv =	 ((lv << 1) |
-			(((lv >> 15) ^ (lv >> 4) ^ (lv >> 2) ^ (lv >> 1)) & 1))
-			& 0xFFFF;
-	}
-
-	return (u16) lv;
-}
-
-/*
- * This does LFSR conversion on the value that is to be written.
- * See LFSR explanation above for more detail.
- */
-static char *dlfb_set_register_lfsr16(char *wrptr, u8 reg, u16 value)
-{
-	return dlfb_set_register_16(wrptr, reg, dlfb_lfsr16(value));
-}
-
-/*
- * This takes a standard fbdev screeninfo struct and all of its monitor mode
- * details and converts them into the DisplayLink equivalent register commands.
- */
-static char *dlfb_set_vid_cmds(char *wrptr, struct fb_var_screeninfo *var)
-{
-	u16 xds, yds;
-	u16 xde, yde;
-	u16 yec;
-
-	/* x display start */
-	xds = var->left_margin + var->hsync_len;
-	wrptr = dlfb_set_register_lfsr16(wrptr, 0x01, xds);
-	/* x display end */
-	xde = xds + var->xres;
-	wrptr = dlfb_set_register_lfsr16(wrptr, 0x03, xde);
-
-	/* y display start */
-	yds = var->upper_margin + var->vsync_len;
-	wrptr = dlfb_set_register_lfsr16(wrptr, 0x05, yds);
-	/* y display end */
-	yde = yds + var->yres;
-	wrptr = dlfb_set_register_lfsr16(wrptr, 0x07, yde);
-
-	/* x end count is active + blanking - 1 */
-	wrptr = dlfb_set_register_lfsr16(wrptr, 0x09,
-			xde + var->right_margin - 1);
-
-	/* libdlo hardcodes hsync start to 1 */
-	wrptr = dlfb_set_register_lfsr16(wrptr, 0x0B, 1);
-
-	/* hsync end is width of sync pulse + 1 */
-	wrptr = dlfb_set_register_lfsr16(wrptr, 0x0D, var->hsync_len + 1);
-
-	/* hpixels is active pixels */
-	wrptr = dlfb_set_register_16(wrptr, 0x0F, var->xres);
-
-	/* yendcount is vertical active + vertical blanking */
-	yec = var->yres + var->upper_margin + var->lower_margin +
-			var->vsync_len;
-	wrptr = dlfb_set_register_lfsr16(wrptr, 0x11, yec);
-
-	/* libdlo hardcodes vsync start to 0 */
-	wrptr = dlfb_set_register_lfsr16(wrptr, 0x13, 0);
-
-	/* vsync end is width of vsync pulse */
-	wrptr = dlfb_set_register_lfsr16(wrptr, 0x15, var->vsync_len);
-
-	/* vpixels is active pixels */
-	wrptr = dlfb_set_register_16(wrptr, 0x17, var->yres);
-
-	/* convert picoseconds to 5kHz multiple for pclk5k = x * 1E12/5k */
-	wrptr = dlfb_set_register_16be(wrptr, 0x1B,
-			200*1000*1000/var->pixclock);
-
-	return wrptr;
-}
-
-/*
- * This takes a standard fbdev screeninfo struct that was fetched or prepared
- * and then generates the appropriate command sequence that then drives the
- * display controller.
- */
-static int dlfb_set_video_mode(struct dlfb_data *dlfb,
-				struct fb_var_screeninfo *var)
-{
-	char *buf;
-	char *wrptr;
-	int retval;
-	int writesize;
-	struct urb *urb;
-
-	if (!atomic_read(&dlfb->usb_active))
-		return -EPERM;
-
-	urb = dlfb_get_urb(dlfb);
-	if (!urb)
-		return -ENOMEM;
-
-	buf = (char *) urb->transfer_buffer;
-
-	/*
-	* This first section has to do with setting the base address on the
-	* controller * associated with the display. There are 2 base
-	* pointers, currently, we only * use the 16 bpp segment.
-	*/
-	wrptr = dlfb_vidreg_lock(buf);
-	wrptr = dlfb_set_color_depth(wrptr, 0x00);
-	/* set base for 16bpp segment to 0 */
-	wrptr = dlfb_set_base16bpp(wrptr, 0);
-	/* set base for 8bpp segment to end of fb */
-	wrptr = dlfb_set_base8bpp(wrptr, dlfb->info->fix.smem_len);
-
-	wrptr = dlfb_set_vid_cmds(wrptr, var);
-	wrptr = dlfb_blanking(wrptr, FB_BLANK_UNBLANK);
-	wrptr = dlfb_vidreg_unlock(wrptr);
-
-	writesize = wrptr - buf;
-
-	retval = dlfb_submit_urb(dlfb, urb, writesize);
-
-	dlfb->blank_mode = FB_BLANK_UNBLANK;
-
-	return retval;
-}
-
-static int dlfb_ops_mmap(struct fb_info *info, struct vm_area_struct *vma)
-{
-	unsigned long start = vma->vm_start;
-	unsigned long size = vma->vm_end - vma->vm_start;
-	unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
-	unsigned long page, pos;
-
-	if (vma->vm_pgoff > (~0UL >> PAGE_SHIFT))
-		return -EINVAL;
-	if (size > info->fix.smem_len)
-		return -EINVAL;
-	if (offset > info->fix.smem_len - size)
-		return -EINVAL;
-
-	pos = (unsigned long)info->fix.smem_start + offset;
-
-	dev_dbg(info->dev, "mmap() framebuffer addr:%lu size:%lu\n",
-		pos, size);
-
-	while (size > 0) {
-		page = vmalloc_to_pfn((void *)pos);
-		if (remap_pfn_range(vma, start, page, PAGE_SIZE, PAGE_SHARED))
-			return -EAGAIN;
-
-		start += PAGE_SIZE;
-		pos += PAGE_SIZE;
-		if (size > PAGE_SIZE)
-			size -= PAGE_SIZE;
-		else
-			size = 0;
-	}
-
-	return 0;
-}
-
-/*
- * Trims identical data from front and back of line
- * Sets new front buffer address and width
- * And returns byte count of identical pixels
- * Assumes CPU natural alignment (unsigned long)
- * for back and front buffer ptrs and width
- */
-static int dlfb_trim_hline(const u8 *bback, const u8 **bfront, int *width_bytes)
-{
-	int j, k;
-	const unsigned long *back = (const unsigned long *) bback;
-	const unsigned long *front = (const unsigned long *) *bfront;
-	const int width = *width_bytes / sizeof(unsigned long);
-	int identical = width;
-	int start = width;
-	int end = width;
-
-	for (j = 0; j < width; j++) {
-		if (back[j] != front[j]) {
-			start = j;
-			break;
-		}
-	}
-
-	for (k = width - 1; k > j; k--) {
-		if (back[k] != front[k]) {
-			end = k+1;
-			break;
-		}
-	}
-
-	identical = start + (width - end);
-	*bfront = (u8 *) &front[start];
-	*width_bytes = (end - start) * sizeof(unsigned long);
-
-	return identical * sizeof(unsigned long);
-}
-
-/*
- * Render a command stream for an encoded horizontal line segment of pixels.
- *
- * A command buffer holds several commands.
- * It always begins with a fresh command header
- * (the protocol doesn't require this, but we enforce it to allow
- * multiple buffers to be potentially encoded and sent in parallel).
- * A single command encodes one contiguous horizontal line of pixels
- *
- * The function relies on the client to do all allocation, so that
- * rendering can be done directly to output buffers (e.g. USB URBs).
- * The function fills the supplied command buffer, providing information
- * on where it left off, so the client may call in again with additional
- * buffers if the line will take several buffers to complete.
- *
- * A single command can transmit a maximum of 256 pixels,
- * regardless of the compression ratio (protocol design limit).
- * To the hardware, 0 for a size byte means 256
- *
- * Rather than 256 pixel commands which are either rl or raw encoded,
- * the rlx command simply assumes alternating raw and rl spans within one cmd.
- * This has a slightly larger header overhead, but produces more even results.
- * It also processes all data (read and write) in a single pass.
- * Performance benchmarks of common cases show it having just slightly better
- * compression than 256 pixel raw or rle commands, with similar CPU consumpion.
- * But for very rl friendly data, will compress not quite as well.
- */
-static void dlfb_compress_hline(
-	const uint16_t **pixel_start_ptr,
-	const uint16_t *const pixel_end,
-	uint32_t *device_address_ptr,
-	uint8_t **command_buffer_ptr,
-	const uint8_t *const cmd_buffer_end,
-	unsigned long back_buffer_offset,
-	int *ident_ptr)
-{
-	const uint16_t *pixel = *pixel_start_ptr;
-	uint32_t dev_addr  = *device_address_ptr;
-	uint8_t *cmd = *command_buffer_ptr;
-
-	while ((pixel_end > pixel) &&
-	       (cmd_buffer_end - MIN_RLX_CMD_BYTES > cmd)) {
-		uint8_t *raw_pixels_count_byte = NULL;
-		uint8_t *cmd_pixels_count_byte = NULL;
-		const uint16_t *raw_pixel_start = NULL;
-		const uint16_t *cmd_pixel_start, *cmd_pixel_end = NULL;
-
-		if (back_buffer_offset &&
-		    *pixel == *(u16 *)((u8 *)pixel + back_buffer_offset)) {
-			pixel++;
-			dev_addr += BPP;
-			(*ident_ptr)++;
-			continue;
-		}
-
-		*cmd++ = 0xAF;
-		*cmd++ = 0x6B;
-		*cmd++ = dev_addr >> 16;
-		*cmd++ = dev_addr >> 8;
-		*cmd++ = dev_addr;
-
-		cmd_pixels_count_byte = cmd++; /*  we'll know this later */
-		cmd_pixel_start = pixel;
-
-		raw_pixels_count_byte = cmd++; /*  we'll know this later */
-		raw_pixel_start = pixel;
-
-		cmd_pixel_end = pixel + min3(MAX_CMD_PIXELS + 1UL,
-					(unsigned long)(pixel_end - pixel),
-					(unsigned long)(cmd_buffer_end - 1 - cmd) / BPP);
-
-		if (back_buffer_offset) {
-			/* note: the framebuffer may change under us, so we must test for underflow */
-			while (cmd_pixel_end - 1 > pixel &&
-			       *(cmd_pixel_end - 1) == *(u16 *)((u8 *)(cmd_pixel_end - 1) + back_buffer_offset))
-				cmd_pixel_end--;
-		}
-
-		while (pixel < cmd_pixel_end) {
-			const uint16_t * const repeating_pixel = pixel;
-			u16 pixel_value = *pixel;
-
-			put_unaligned_be16(pixel_value, cmd);
-			if (back_buffer_offset)
-				*(u16 *)((u8 *)pixel + back_buffer_offset) = pixel_value;
-			cmd += 2;
-			pixel++;
-
-			if (unlikely((pixel < cmd_pixel_end) &&
-				     (*pixel == pixel_value))) {
-				/* go back and fill in raw pixel count */
-				*raw_pixels_count_byte = ((repeating_pixel -
-						raw_pixel_start) + 1) & 0xFF;
-
-				do {
-					if (back_buffer_offset)
-						*(u16 *)((u8 *)pixel + back_buffer_offset) = pixel_value;
-					pixel++;
-				} while ((pixel < cmd_pixel_end) &&
-					 (*pixel == pixel_value));
-
-				/* immediately after raw data is repeat byte */
-				*cmd++ = ((pixel - repeating_pixel) - 1) & 0xFF;
-
-				/* Then start another raw pixel span */
-				raw_pixel_start = pixel;
-				raw_pixels_count_byte = cmd++;
-			}
-		}
-
-		if (pixel > raw_pixel_start) {
-			/* finalize last RAW span */
-			*raw_pixels_count_byte = (pixel-raw_pixel_start) & 0xFF;
-		} else {
-			/* undo unused byte */
-			cmd--;
-		}
-
-		*cmd_pixels_count_byte = (pixel - cmd_pixel_start) & 0xFF;
-		dev_addr += (u8 *)pixel - (u8 *)cmd_pixel_start;
-	}
-
-	if (cmd_buffer_end - MIN_RLX_CMD_BYTES <= cmd) {
-		/* Fill leftover bytes with no-ops */
-		if (cmd_buffer_end > cmd)
-			memset(cmd, 0xAF, cmd_buffer_end - cmd);
-		cmd = (uint8_t *) cmd_buffer_end;
-	}
-
-	*command_buffer_ptr = cmd;
-	*pixel_start_ptr = pixel;
-	*device_address_ptr = dev_addr;
-}
-
-/*
- * There are 3 copies of every pixel: The front buffer that the fbdev
- * client renders to, the actual framebuffer across the USB bus in hardware
- * (that we can only write to, slowly, and can never read), and (optionally)
- * our shadow copy that tracks what's been sent to that hardware buffer.
- */
-static int dlfb_render_hline(struct dlfb_data *dlfb, struct urb **urb_ptr,
-			      const char *front, char **urb_buf_ptr,
-			      u32 byte_offset, u32 byte_width,
-			      int *ident_ptr, int *sent_ptr)
-{
-	const u8 *line_start, *line_end, *next_pixel;
-	u32 dev_addr = dlfb->base16 + byte_offset;
-	struct urb *urb = *urb_ptr;
-	u8 *cmd = *urb_buf_ptr;
-	u8 *cmd_end = (u8 *) urb->transfer_buffer + urb->transfer_buffer_length;
-	unsigned long back_buffer_offset = 0;
-
-	line_start = (u8 *) (front + byte_offset);
-	next_pixel = line_start;
-	line_end = next_pixel + byte_width;
-
-	if (dlfb->backing_buffer) {
-		int offset;
-		const u8 *back_start = (u8 *) (dlfb->backing_buffer
-						+ byte_offset);
-
-		back_buffer_offset = (unsigned long)back_start - (unsigned long)line_start;
-
-		*ident_ptr += dlfb_trim_hline(back_start, &next_pixel,
-			&byte_width);
-
-		offset = next_pixel - line_start;
-		line_end = next_pixel + byte_width;
-		dev_addr += offset;
-		back_start += offset;
-		line_start += offset;
-	}
-
-	while (next_pixel < line_end) {
-
-		dlfb_compress_hline((const uint16_t **) &next_pixel,
-			     (const uint16_t *) line_end, &dev_addr,
-			(u8 **) &cmd, (u8 *) cmd_end, back_buffer_offset,
-			ident_ptr);
-
-		if (cmd >= cmd_end) {
-			int len = cmd - (u8 *) urb->transfer_buffer;
-			if (dlfb_submit_urb(dlfb, urb, len))
-				return 1; /* lost pixels is set */
-			*sent_ptr += len;
-			urb = dlfb_get_urb(dlfb);
-			if (!urb)
-				return 1; /* lost_pixels is set */
-			*urb_ptr = urb;
-			cmd = urb->transfer_buffer;
-			cmd_end = &cmd[urb->transfer_buffer_length];
-		}
-	}
-
-	*urb_buf_ptr = cmd;
-
-	return 0;
-}
-
-static int dlfb_handle_damage(struct dlfb_data *dlfb, int x, int y, int width, int height)
-{
-	int i, ret;
-	char *cmd;
-	cycles_t start_cycles, end_cycles;
-	int bytes_sent = 0;
-	int bytes_identical = 0;
-	struct urb *urb;
-	int aligned_x;
-
-	start_cycles = get_cycles();
-
-	mutex_lock(&dlfb->render_mutex);
-
-	aligned_x = DL_ALIGN_DOWN(x, sizeof(unsigned long));
-	width = DL_ALIGN_UP(width + (x-aligned_x), sizeof(unsigned long));
-	x = aligned_x;
-
-	if ((width <= 0) ||
-	    (x + width > dlfb->info->var.xres) ||
-	    (y + height > dlfb->info->var.yres)) {
-		ret = -EINVAL;
-		goto unlock_ret;
-	}
-
-	if (!atomic_read(&dlfb->usb_active)) {
-		ret = 0;
-		goto unlock_ret;
-	}
-
-	urb = dlfb_get_urb(dlfb);
-	if (!urb) {
-		ret = 0;
-		goto unlock_ret;
-	}
-	cmd = urb->transfer_buffer;
-
-	for (i = y; i < y + height ; i++) {
-		const int line_offset = dlfb->info->fix.line_length * i;
-		const int byte_offset = line_offset + (x * BPP);
-
-		if (dlfb_render_hline(dlfb, &urb,
-				      (char *) dlfb->info->fix.smem_start,
-				      &cmd, byte_offset, width * BPP,
-				      &bytes_identical, &bytes_sent))
-			goto error;
-	}
-
-	if (cmd > (char *) urb->transfer_buffer) {
-		int len;
-		if (cmd < (char *) urb->transfer_buffer + urb->transfer_buffer_length)
-			*cmd++ = 0xAF;
-		/* Send partial buffer remaining before exiting */
-		len = cmd - (char *) urb->transfer_buffer;
-		dlfb_submit_urb(dlfb, urb, len);
-		bytes_sent += len;
-	} else
-		dlfb_urb_completion(urb);
-
-error:
-	atomic_add(bytes_sent, &dlfb->bytes_sent);
-	atomic_add(bytes_identical, &dlfb->bytes_identical);
-	atomic_add(width*height*2, &dlfb->bytes_rendered);
-	end_cycles = get_cycles();
-	atomic_add(((unsigned int) ((end_cycles - start_cycles)
-		    >> 10)), /* Kcycles */
-		   &dlfb->cpu_kcycles_used);
-
-	ret = 0;
-
-unlock_ret:
-	mutex_unlock(&dlfb->render_mutex);
-	return ret;
-}
-
-static void dlfb_init_damage(struct dlfb_data *dlfb)
-{
-	dlfb->damage_x = INT_MAX;
-	dlfb->damage_x2 = 0;
-	dlfb->damage_y = INT_MAX;
-	dlfb->damage_y2 = 0;
-}
-
-static void dlfb_damage_work(struct work_struct *w)
-{
-	struct dlfb_data *dlfb = container_of(w, struct dlfb_data, damage_work);
-	int x, x2, y, y2;
-
-	spin_lock_irq(&dlfb->damage_lock);
-	x = dlfb->damage_x;
-	x2 = dlfb->damage_x2;
-	y = dlfb->damage_y;
-	y2 = dlfb->damage_y2;
-	dlfb_init_damage(dlfb);
-	spin_unlock_irq(&dlfb->damage_lock);
-
-	if (x < x2 && y < y2)
-		dlfb_handle_damage(dlfb, x, y, x2 - x, y2 - y);
-}
-
-static void dlfb_offload_damage(struct dlfb_data *dlfb, int x, int y, int width, int height)
-{
-	unsigned long flags;
-	int x2 = x + width;
-	int y2 = y + height;
-
-	if (x >= x2 || y >= y2)
-		return;
-
-	spin_lock_irqsave(&dlfb->damage_lock, flags);
-	dlfb->damage_x = min(x, dlfb->damage_x);
-	dlfb->damage_x2 = max(x2, dlfb->damage_x2);
-	dlfb->damage_y = min(y, dlfb->damage_y);
-	dlfb->damage_y2 = max(y2, dlfb->damage_y2);
-	spin_unlock_irqrestore(&dlfb->damage_lock, flags);
-
-	schedule_work(&dlfb->damage_work);
-}
-
-/*
- * Path triggered by usermode clients who write to filesystem
- * e.g. cat filename > /dev/fb1
- * Not used by X Windows or text-mode console. But useful for testing.
- * Slow because of extra copy and we must assume all pixels dirty.
- */
-static ssize_t dlfb_ops_write(struct fb_info *info, const char __user *buf,
-			  size_t count, loff_t *ppos)
-{
-	ssize_t result;
-	struct dlfb_data *dlfb = info->par;
-	u32 offset = (u32) *ppos;
-
-	result = fb_sys_write(info, buf, count, ppos);
-
-	if (result > 0) {
-		int start = max((int)(offset / info->fix.line_length), 0);
-		int lines = min((u32)((result / info->fix.line_length) + 1),
-				(u32)info->var.yres);
-
-		dlfb_handle_damage(dlfb, 0, start, info->var.xres,
-			lines);
-	}
-
-	return result;
-}
-
-/* hardware has native COPY command (see libdlo), but not worth it for fbcon */
-static void dlfb_ops_copyarea(struct fb_info *info,
-				const struct fb_copyarea *area)
-{
-
-	struct dlfb_data *dlfb = info->par;
-
-	sys_copyarea(info, area);
-
-	dlfb_offload_damage(dlfb, area->dx, area->dy,
-			area->width, area->height);
-}
-
-static void dlfb_ops_imageblit(struct fb_info *info,
-				const struct fb_image *image)
-{
-	struct dlfb_data *dlfb = info->par;
-
-	sys_imageblit(info, image);
-
-	dlfb_offload_damage(dlfb, image->dx, image->dy,
-			image->width, image->height);
-}
-
-static void dlfb_ops_fillrect(struct fb_info *info,
-			  const struct fb_fillrect *rect)
-{
-	struct dlfb_data *dlfb = info->par;
-
-	sys_fillrect(info, rect);
-
-	dlfb_offload_damage(dlfb, rect->dx, rect->dy, rect->width,
-			      rect->height);
-}
-
-/*
- * NOTE: fb_defio.c is holding info->fbdefio.mutex
- *   Touching ANY framebuffer memory that triggers a page fault
- *   in fb_defio will cause a deadlock, when it also tries to
- *   grab the same mutex.
- */
-static void dlfb_dpy_deferred_io(struct fb_info *info,
-				struct list_head *pagelist)
-{
-	struct page *cur;
-	struct fb_deferred_io *fbdefio = info->fbdefio;
-	struct dlfb_data *dlfb = info->par;
-	struct urb *urb;
-	char *cmd;
-	cycles_t start_cycles, end_cycles;
-	int bytes_sent = 0;
-	int bytes_identical = 0;
-	int bytes_rendered = 0;
-
-	mutex_lock(&dlfb->render_mutex);
-
-	if (!fb_defio)
-		goto unlock_ret;
-
-	if (!atomic_read(&dlfb->usb_active))
-		goto unlock_ret;
-
-	start_cycles = get_cycles();
-
-	urb = dlfb_get_urb(dlfb);
-	if (!urb)
-		goto unlock_ret;
-
-	cmd = urb->transfer_buffer;
-
-	/* walk the written page list and render each to device */
-	list_for_each_entry(cur, &fbdefio->pagelist, lru) {
-
-		if (dlfb_render_hline(dlfb, &urb, (char *) info->fix.smem_start,
-				  &cmd, cur->index << PAGE_SHIFT,
-				  PAGE_SIZE, &bytes_identical, &bytes_sent))
-			goto error;
-		bytes_rendered += PAGE_SIZE;
-	}
-
-	if (cmd > (char *) urb->transfer_buffer) {
-		int len;
-		if (cmd < (char *) urb->transfer_buffer + urb->transfer_buffer_length)
-			*cmd++ = 0xAF;
-		/* Send partial buffer remaining before exiting */
-		len = cmd - (char *) urb->transfer_buffer;
-		dlfb_submit_urb(dlfb, urb, len);
-		bytes_sent += len;
-	} else
-		dlfb_urb_completion(urb);
-
-error:
-	atomic_add(bytes_sent, &dlfb->bytes_sent);
-	atomic_add(bytes_identical, &dlfb->bytes_identical);
-	atomic_add(bytes_rendered, &dlfb->bytes_rendered);
-	end_cycles = get_cycles();
-	atomic_add(((unsigned int) ((end_cycles - start_cycles)
-		    >> 10)), /* Kcycles */
-		   &dlfb->cpu_kcycles_used);
-unlock_ret:
-	mutex_unlock(&dlfb->render_mutex);
-}
-
-static int dlfb_get_edid(struct dlfb_data *dlfb, char *edid, int len)
-{
-	int i, ret;
-	char *rbuf;
-
-	rbuf = kmalloc(2, GFP_KERNEL);
-	if (!rbuf)
-		return 0;
-
-	for (i = 0; i < len; i++) {
-		ret = usb_control_msg(dlfb->udev,
-				      usb_rcvctrlpipe(dlfb->udev, 0), 0x02,
-				      (0x80 | (0x02 << 5)), i << 8, 0xA1,
-				      rbuf, 2, USB_CTRL_GET_TIMEOUT);
-		if (ret < 2) {
-			dev_err(&dlfb->udev->dev,
-				"Read EDID byte %d failed: %d\n", i, ret);
-			i--;
-			break;
-		}
-		edid[i] = rbuf[1];
-	}
-
-	kfree(rbuf);
-
-	return i;
-}
-
-static int dlfb_ops_ioctl(struct fb_info *info, unsigned int cmd,
-				unsigned long arg)
-{
-
-	struct dlfb_data *dlfb = info->par;
-
-	if (!atomic_read(&dlfb->usb_active))
-		return 0;
-
-	/* TODO: Update X server to get this from sysfs instead */
-	if (cmd == DLFB_IOCTL_RETURN_EDID) {
-		void __user *edid = (void __user *)arg;
-		if (copy_to_user(edid, dlfb->edid, dlfb->edid_size))
-			return -EFAULT;
-		return 0;
-	}
-
-	/* TODO: Help propose a standard fb.h ioctl to report mmap damage */
-	if (cmd == DLFB_IOCTL_REPORT_DAMAGE) {
-		struct dloarea area;
-
-		if (copy_from_user(&area, (void __user *)arg,
-				  sizeof(struct dloarea)))
-			return -EFAULT;
-
-		/*
-		 * If we have a damage-aware client, turn fb_defio "off"
-		 * To avoid perf imact of unnecessary page fault handling.
-		 * Done by resetting the delay for this fb_info to a very
-		 * long period. Pages will become writable and stay that way.
-		 * Reset to normal value when all clients have closed this fb.
-		 */
-		if (info->fbdefio)
-			info->fbdefio->delay = DL_DEFIO_WRITE_DISABLE;
-
-		if (area.x < 0)
-			area.x = 0;
-
-		if (area.x > info->var.xres)
-			area.x = info->var.xres;
-
-		if (area.y < 0)
-			area.y = 0;
-
-		if (area.y > info->var.yres)
-			area.y = info->var.yres;
-
-		dlfb_handle_damage(dlfb, area.x, area.y, area.w, area.h);
-	}
-
-	return 0;
-}
-
-/* taken from vesafb */
-static int
-dlfb_ops_setcolreg(unsigned regno, unsigned red, unsigned green,
-	       unsigned blue, unsigned transp, struct fb_info *info)
-{
-	int err = 0;
-
-	if (regno >= info->cmap.len)
-		return 1;
-
-	if (regno < 16) {
-		if (info->var.red.offset == 10) {
-			/* 1:5:5:5 */
-			((u32 *) (info->pseudo_palette))[regno] =
-			    ((red & 0xf800) >> 1) |
-			    ((green & 0xf800) >> 6) | ((blue & 0xf800) >> 11);
-		} else {
-			/* 0:5:6:5 */
-			((u32 *) (info->pseudo_palette))[regno] =
-			    ((red & 0xf800)) |
-			    ((green & 0xfc00) >> 5) | ((blue & 0xf800) >> 11);
-		}
-	}
-
-	return err;
-}
-
-/*
- * It's common for several clients to have framebuffer open simultaneously.
- * e.g. both fbcon and X. Makes things interesting.
- * Assumes caller is holding info->lock (for open and release at least)
- */
-static int dlfb_ops_open(struct fb_info *info, int user)
-{
-	struct dlfb_data *dlfb = info->par;
-
-	/*
-	 * fbcon aggressively connects to first framebuffer it finds,
-	 * preventing other clients (X) from working properly. Usually
-	 * not what the user wants. Fail by default with option to enable.
-	 */
-	if ((user == 0) && (!console))
-		return -EBUSY;
-
-	/* If the USB device is gone, we don't accept new opens */
-	if (dlfb->virtualized)
-		return -ENODEV;
-
-	dlfb->fb_count++;
-
-	if (fb_defio && (info->fbdefio == NULL)) {
-		/* enable defio at last moment if not disabled by client */
-
-		struct fb_deferred_io *fbdefio;
-
-		fbdefio = kzalloc(sizeof(struct fb_deferred_io), GFP_KERNEL);
-
-		if (fbdefio) {
-			fbdefio->delay = DL_DEFIO_WRITE_DELAY;
-			fbdefio->deferred_io = dlfb_dpy_deferred_io;
-		}
-
-		info->fbdefio = fbdefio;
-		fb_deferred_io_init(info);
-	}
-
-	dev_dbg(info->dev, "open, user=%d fb_info=%p count=%d\n",
-		user, info, dlfb->fb_count);
-
-	return 0;
-}
-
-static void dlfb_ops_destroy(struct fb_info *info)
-{
-	struct dlfb_data *dlfb = info->par;
-
-	cancel_work_sync(&dlfb->damage_work);
-
-	mutex_destroy(&dlfb->render_mutex);
-
-	if (info->cmap.len != 0)
-		fb_dealloc_cmap(&info->cmap);
-	if (info->monspecs.modedb)
-		fb_destroy_modedb(info->monspecs.modedb);
-	vfree(info->screen_base);
-
-	fb_destroy_modelist(&info->modelist);
-
-	while (!list_empty(&dlfb->deferred_free)) {
-		struct dlfb_deferred_free *d = list_entry(dlfb->deferred_free.next, struct dlfb_deferred_free, list);
-		list_del(&d->list);
-		vfree(d->mem);
-		kfree(d);
-	}
-	vfree(dlfb->backing_buffer);
-	kfree(dlfb->edid);
-	usb_put_dev(dlfb->udev);
-	kfree(dlfb);
-
-	/* Assume info structure is freed after this point */
-	framebuffer_release(info);
-}
-
-/*
- * Assumes caller is holding info->lock mutex (for open and release at least)
- */
-static int dlfb_ops_release(struct fb_info *info, int user)
-{
-	struct dlfb_data *dlfb = info->par;
-
-	dlfb->fb_count--;
-
-	if ((dlfb->fb_count == 0) && (info->fbdefio)) {
-		fb_deferred_io_cleanup(info);
-		kfree(info->fbdefio);
-		info->fbdefio = NULL;
-	}
-
-	dev_dbg(info->dev, "release, user=%d count=%d\n", user, dlfb->fb_count);
-
-	return 0;
-}
-
-/*
- * Check whether a video mode is supported by the DisplayLink chip
- * We start from monitor's modes, so don't need to filter that here
- */
-static int dlfb_is_valid_mode(struct fb_videomode *mode, struct dlfb_data *dlfb)
-{
-	if (mode->xres * mode->yres > dlfb->sku_pixel_limit)
-		return 0;
-
-	return 1;
-}
-
-static void dlfb_var_color_format(struct fb_var_screeninfo *var)
-{
-	const struct fb_bitfield red = { 11, 5, 0 };
-	const struct fb_bitfield green = { 5, 6, 0 };
-	const struct fb_bitfield blue = { 0, 5, 0 };
-
-	var->bits_per_pixel = 16;
-	var->red = red;
-	var->green = green;
-	var->blue = blue;
-}
-
-static int dlfb_ops_check_var(struct fb_var_screeninfo *var,
-				struct fb_info *info)
-{
-	struct fb_videomode mode;
-	struct dlfb_data *dlfb = info->par;
-
-	/* set device-specific elements of var unrelated to mode */
-	dlfb_var_color_format(var);
-
-	fb_var_to_videomode(&mode, var);
-
-	if (!dlfb_is_valid_mode(&mode, dlfb))
-		return -EINVAL;
-
-	return 0;
-}
-
-static int dlfb_ops_set_par(struct fb_info *info)
-{
-	struct dlfb_data *dlfb = info->par;
-	int result;
-	u16 *pix_framebuffer;
-	int i;
-	struct fb_var_screeninfo fvs;
-	u32 line_length = info->var.xres * (info->var.bits_per_pixel / 8);
-
-	/* clear the activate field because it causes spurious miscompares */
-	fvs = info->var;
-	fvs.activate = 0;
-	fvs.vmode &= ~FB_VMODE_SMOOTH_XPAN;
-
-	if (!memcmp(&dlfb->current_mode, &fvs, sizeof(struct fb_var_screeninfo)))
-		return 0;
-
-	result = dlfb_realloc_framebuffer(dlfb, info, info->var.yres * line_length);
-	if (result)
-		return result;
-
-	result = dlfb_set_video_mode(dlfb, &info->var);
-
-	if (result)
-		return result;
-
-	dlfb->current_mode = fvs;
-	info->fix.line_length = line_length;
-
-	if (dlfb->fb_count == 0) {
-
-		/* paint greenscreen */
-
-		pix_framebuffer = (u16 *) info->screen_base;
-		for (i = 0; i < info->fix.smem_len / 2; i++)
-			pix_framebuffer[i] = 0x37e6;
-	}
-
-	dlfb_handle_damage(dlfb, 0, 0, info->var.xres, info->var.yres);
-
-	return 0;
-}
-
-/* To fonzi the jukebox (e.g. make blanking changes take effect) */
-static char *dlfb_dummy_render(char *buf)
-{
-	*buf++ = 0xAF;
-	*buf++ = 0x6A; /* copy */
-	*buf++ = 0x00; /* from address*/
-	*buf++ = 0x00;
-	*buf++ = 0x00;
-	*buf++ = 0x01; /* one pixel */
-	*buf++ = 0x00; /* to address */
-	*buf++ = 0x00;
-	*buf++ = 0x00;
-	return buf;
-}
-
-/*
- * In order to come back from full DPMS off, we need to set the mode again
- */
-static int dlfb_ops_blank(int blank_mode, struct fb_info *info)
-{
-	struct dlfb_data *dlfb = info->par;
-	char *bufptr;
-	struct urb *urb;
-
-	dev_dbg(info->dev, "blank, mode %d --> %d\n",
-		dlfb->blank_mode, blank_mode);
-
-	if ((dlfb->blank_mode == FB_BLANK_POWERDOWN) &&
-	    (blank_mode != FB_BLANK_POWERDOWN)) {
-
-		/* returning from powerdown requires a fresh modeset */
-		dlfb_set_video_mode(dlfb, &info->var);
-	}
-
-	urb = dlfb_get_urb(dlfb);
-	if (!urb)
-		return 0;
-
-	bufptr = (char *) urb->transfer_buffer;
-	bufptr = dlfb_vidreg_lock(bufptr);
-	bufptr = dlfb_blanking(bufptr, blank_mode);
-	bufptr = dlfb_vidreg_unlock(bufptr);
-
-	/* seems like a render op is needed to have blank change take effect */
-	bufptr = dlfb_dummy_render(bufptr);
-
-	dlfb_submit_urb(dlfb, urb, bufptr -
-			(char *) urb->transfer_buffer);
-
-	dlfb->blank_mode = blank_mode;
-
-	return 0;
-}
-
-static const struct fb_ops dlfb_ops = {
-	.owner = THIS_MODULE,
-	.fb_read = fb_sys_read,
-	.fb_write = dlfb_ops_write,
-	.fb_setcolreg = dlfb_ops_setcolreg,
-	.fb_fillrect = dlfb_ops_fillrect,
-	.fb_copyarea = dlfb_ops_copyarea,
-	.fb_imageblit = dlfb_ops_imageblit,
-	.fb_mmap = dlfb_ops_mmap,
-	.fb_ioctl = dlfb_ops_ioctl,
-	.fb_open = dlfb_ops_open,
-	.fb_release = dlfb_ops_release,
-	.fb_blank = dlfb_ops_blank,
-	.fb_check_var = dlfb_ops_check_var,
-	.fb_set_par = dlfb_ops_set_par,
-	.fb_destroy = dlfb_ops_destroy,
-};
-
-
-static void dlfb_deferred_vfree(struct dlfb_data *dlfb, void *mem)
-{
-	struct dlfb_deferred_free *d = kmalloc(sizeof(struct dlfb_deferred_free), GFP_KERNEL);
-	if (!d)
-		return;
-	d->mem = mem;
-	list_add(&d->list, &dlfb->deferred_free);
-}
-
-/*
- * Assumes &info->lock held by caller
- * Assumes no active clients have framebuffer open
- */
-static int dlfb_realloc_framebuffer(struct dlfb_data *dlfb, struct fb_info *info, u32 new_len)
-{
-	u32 old_len = info->fix.smem_len;
-	const void *old_fb = (const void __force *)info->screen_base;
-	unsigned char *new_fb;
-	unsigned char *new_back = NULL;
-
-	new_len = PAGE_ALIGN(new_len);
-
-	if (new_len > old_len) {
-		/*
-		 * Alloc system memory for virtual framebuffer
-		 */
-		new_fb = vmalloc(new_len);
-		if (!new_fb) {
-			dev_err(info->dev, "Virtual framebuffer alloc failed\n");
-			return -ENOMEM;
-		}
-		memset(new_fb, 0xff, new_len);
-
-		if (info->screen_base) {
-			memcpy(new_fb, old_fb, old_len);
-			dlfb_deferred_vfree(dlfb, (void __force *)info->screen_base);
-		}
-
-		info->screen_base = (char __iomem *)new_fb;
-		info->fix.smem_len = new_len;
-		info->fix.smem_start = (unsigned long) new_fb;
-		info->flags = udlfb_info_flags;
-
-		/*
-		 * Second framebuffer copy to mirror the framebuffer state
-		 * on the physical USB device. We can function without this.
-		 * But with imperfect damage info we may send pixels over USB
-		 * that were, in fact, unchanged - wasting limited USB bandwidth
-		 */
-		if (shadow)
-			new_back = vzalloc(new_len);
-		if (!new_back)
-			dev_info(info->dev,
-				 "No shadow/backing buffer allocated\n");
-		else {
-			dlfb_deferred_vfree(dlfb, dlfb->backing_buffer);
-			dlfb->backing_buffer = new_back;
-		}
-	}
-	return 0;
-}
-
-/*
- * 1) Get EDID from hw, or use sw default
- * 2) Parse into various fb_info structs
- * 3) Allocate virtual framebuffer memory to back highest res mode
- *
- * Parses EDID into three places used by various parts of fbdev:
- * fb_var_screeninfo contains the timing of the monitor's preferred mode
- * fb_info.monspecs is full parsed EDID info, including monspecs.modedb
- * fb_info.modelist is a linked list of all monitor & VESA modes which work
- *
- * If EDID is not readable/valid, then modelist is all VESA modes,
- * monspecs is NULL, and fb_var_screeninfo is set to safe VESA mode
- * Returns 0 if successful
- */
-static int dlfb_setup_modes(struct dlfb_data *dlfb,
-			   struct fb_info *info,
-			   char *default_edid, size_t default_edid_size)
-{
-	char *edid;
-	int i, result = 0, tries = 3;
-	struct device *dev = info->device;
-	struct fb_videomode *mode;
-	const struct fb_videomode *default_vmode = NULL;
-
-	if (info->dev) {
-		/* only use mutex if info has been registered */
-		mutex_lock(&info->lock);
-		/* parent device is used otherwise */
-		dev = info->dev;
-	}
-
-	edid = kmalloc(EDID_LENGTH, GFP_KERNEL);
-	if (!edid) {
-		result = -ENOMEM;
-		goto error;
-	}
-
-	fb_destroy_modelist(&info->modelist);
-	memset(&info->monspecs, 0, sizeof(info->monspecs));
-
-	/*
-	 * Try to (re)read EDID from hardware first
-	 * EDID data may return, but not parse as valid
-	 * Try again a few times, in case of e.g. analog cable noise
-	 */
-	while (tries--) {
-
-		i = dlfb_get_edid(dlfb, edid, EDID_LENGTH);
-
-		if (i >= EDID_LENGTH)
-			fb_edid_to_monspecs(edid, &info->monspecs);
-
-		if (info->monspecs.modedb_len > 0) {
-			dlfb->edid = edid;
-			dlfb->edid_size = i;
-			break;
-		}
-	}
-
-	/* If that fails, use a previously returned EDID if available */
-	if (info->monspecs.modedb_len == 0) {
-		dev_err(dev, "Unable to get valid EDID from device/display\n");
-
-		if (dlfb->edid) {
-			fb_edid_to_monspecs(dlfb->edid, &info->monspecs);
-			if (info->monspecs.modedb_len > 0)
-				dev_err(dev, "Using previously queried EDID\n");
-		}
-	}
-
-	/* If that fails, use the default EDID we were handed */
-	if (info->monspecs.modedb_len == 0) {
-		if (default_edid_size >= EDID_LENGTH) {
-			fb_edid_to_monspecs(default_edid, &info->monspecs);
-			if (info->monspecs.modedb_len > 0) {
-				memcpy(edid, default_edid, default_edid_size);
-				dlfb->edid = edid;
-				dlfb->edid_size = default_edid_size;
-				dev_err(dev, "Using default/backup EDID\n");
-			}
-		}
-	}
-
-	/* If we've got modes, let's pick a best default mode */
-	if (info->monspecs.modedb_len > 0) {
-
-		for (i = 0; i < info->monspecs.modedb_len; i++) {
-			mode = &info->monspecs.modedb[i];
-			if (dlfb_is_valid_mode(mode, dlfb)) {
-				fb_add_videomode(mode, &info->modelist);
-			} else {
-				dev_dbg(dev, "Specified mode %dx%d too big\n",
-					mode->xres, mode->yres);
-				if (i == 0)
-					/* if we've removed top/best mode */
-					info->monspecs.misc
-						&= ~FB_MISC_1ST_DETAIL;
-			}
-		}
-
-		default_vmode = fb_find_best_display(&info->monspecs,
-						     &info->modelist);
-	}
-
-	/* If everything else has failed, fall back to safe default mode */
-	if (default_vmode == NULL) {
-
-		struct fb_videomode fb_vmode = {0};
-
-		/*
-		 * Add the standard VESA modes to our modelist
-		 * Since we don't have EDID, there may be modes that
-		 * overspec monitor and/or are incorrect aspect ratio, etc.
-		 * But at least the user has a chance to choose
-		 */
-		for (i = 0; i < VESA_MODEDB_SIZE; i++) {
-			mode = (struct fb_videomode *)&vesa_modes[i];
-			if (dlfb_is_valid_mode(mode, dlfb))
-				fb_add_videomode(mode, &info->modelist);
-			else
-				dev_dbg(dev, "VESA mode %dx%d too big\n",
-					mode->xres, mode->yres);
-		}
-
-		/*
-		 * default to resolution safe for projectors
-		 * (since they are most common case without EDID)
-		 */
-		fb_vmode.xres = 800;
-		fb_vmode.yres = 600;
-		fb_vmode.refresh = 60;
-		default_vmode = fb_find_nearest_mode(&fb_vmode,
-						     &info->modelist);
-	}
-
-	/* If we have good mode and no active clients*/
-	if ((default_vmode != NULL) && (dlfb->fb_count == 0)) {
-
-		fb_videomode_to_var(&info->var, default_vmode);
-		dlfb_var_color_format(&info->var);
-
-		/*
-		 * with mode size info, we can now alloc our framebuffer.
-		 */
-		memcpy(&info->fix, &dlfb_fix, sizeof(dlfb_fix));
-	} else
-		result = -EINVAL;
-
-error:
-	if (edid && (dlfb->edid != edid))
-		kfree(edid);
-
-	if (info->dev)
-		mutex_unlock(&info->lock);
-
-	return result;
-}
-
-static ssize_t metrics_bytes_rendered_show(struct device *fbdev,
-				   struct device_attribute *a, char *buf) {
-	struct fb_info *fb_info = dev_get_drvdata(fbdev);
-	struct dlfb_data *dlfb = fb_info->par;
-	return snprintf(buf, PAGE_SIZE, "%u\n",
-			atomic_read(&dlfb->bytes_rendered));
-}
-
-static ssize_t metrics_bytes_identical_show(struct device *fbdev,
-				   struct device_attribute *a, char *buf) {
-	struct fb_info *fb_info = dev_get_drvdata(fbdev);
-	struct dlfb_data *dlfb = fb_info->par;
-	return snprintf(buf, PAGE_SIZE, "%u\n",
-			atomic_read(&dlfb->bytes_identical));
-}
-
-static ssize_t metrics_bytes_sent_show(struct device *fbdev,
-				   struct device_attribute *a, char *buf) {
-	struct fb_info *fb_info = dev_get_drvdata(fbdev);
-	struct dlfb_data *dlfb = fb_info->par;
-	return snprintf(buf, PAGE_SIZE, "%u\n",
-			atomic_read(&dlfb->bytes_sent));
-}
-
-static ssize_t metrics_cpu_kcycles_used_show(struct device *fbdev,
-				   struct device_attribute *a, char *buf) {
-	struct fb_info *fb_info = dev_get_drvdata(fbdev);
-	struct dlfb_data *dlfb = fb_info->par;
-	return snprintf(buf, PAGE_SIZE, "%u\n",
-			atomic_read(&dlfb->cpu_kcycles_used));
-}
-
-static ssize_t edid_show(
-			struct file *filp,
-			struct kobject *kobj, struct bin_attribute *a,
-			 char *buf, loff_t off, size_t count) {
-	struct device *fbdev = kobj_to_dev(kobj);
-	struct fb_info *fb_info = dev_get_drvdata(fbdev);
-	struct dlfb_data *dlfb = fb_info->par;
-
-	if (dlfb->edid == NULL)
-		return 0;
-
-	if ((off >= dlfb->edid_size) || (count > dlfb->edid_size))
-		return 0;
-
-	if (off + count > dlfb->edid_size)
-		count = dlfb->edid_size - off;
-
-	memcpy(buf, dlfb->edid, count);
-
-	return count;
-}
-
-static ssize_t edid_store(
-			struct file *filp,
-			struct kobject *kobj, struct bin_attribute *a,
-			char *src, loff_t src_off, size_t src_size) {
-	struct device *fbdev = kobj_to_dev(kobj);
-	struct fb_info *fb_info = dev_get_drvdata(fbdev);
-	struct dlfb_data *dlfb = fb_info->par;
-	int ret;
-
-	/* We only support write of entire EDID at once, no offset*/
-	if ((src_size != EDID_LENGTH) || (src_off != 0))
-		return -EINVAL;
-
-	ret = dlfb_setup_modes(dlfb, fb_info, src, src_size);
-	if (ret)
-		return ret;
-
-	if (!dlfb->edid || memcmp(src, dlfb->edid, src_size))
-		return -EINVAL;
-
-	ret = dlfb_ops_set_par(fb_info);
-	if (ret)
-		return ret;
-
-	return src_size;
-}
-
-static ssize_t metrics_reset_store(struct device *fbdev,
-			   struct device_attribute *attr,
-			   const char *buf, size_t count)
-{
-	struct fb_info *fb_info = dev_get_drvdata(fbdev);
-	struct dlfb_data *dlfb = fb_info->par;
-
-	atomic_set(&dlfb->bytes_rendered, 0);
-	atomic_set(&dlfb->bytes_identical, 0);
-	atomic_set(&dlfb->bytes_sent, 0);
-	atomic_set(&dlfb->cpu_kcycles_used, 0);
-
-	return count;
-}
-
-static const struct bin_attribute edid_attr = {
-	.attr.name = "edid",
-	.attr.mode = 0666,
-	.size = EDID_LENGTH,
-	.read = edid_show,
-	.write = edid_store
-};
-
-static const struct device_attribute fb_device_attrs[] = {
-	__ATTR_RO(metrics_bytes_rendered),
-	__ATTR_RO(metrics_bytes_identical),
-	__ATTR_RO(metrics_bytes_sent),
-	__ATTR_RO(metrics_cpu_kcycles_used),
-	__ATTR(metrics_reset, S_IWUSR, NULL, metrics_reset_store),
-};
-
-/*
- * This is necessary before we can communicate with the display controller.
- */
-static int dlfb_select_std_channel(struct dlfb_data *dlfb)
-{
-	int ret;
-	void *buf;
-	static const u8 set_def_chn[] = {
-				0x57, 0xCD, 0xDC, 0xA7,
-				0x1C, 0x88, 0x5E, 0x15,
-				0x60, 0xFE, 0xC6, 0x97,
-				0x16, 0x3D, 0x47, 0xF2  };
-
-	buf = kmemdup(set_def_chn, sizeof(set_def_chn), GFP_KERNEL);
-
-	if (!buf)
-		return -ENOMEM;
-
-	ret = usb_control_msg(dlfb->udev, usb_sndctrlpipe(dlfb->udev, 0),
-			NR_USB_REQUEST_CHANNEL,
-			(USB_DIR_OUT | USB_TYPE_VENDOR), 0, 0,
-			buf, sizeof(set_def_chn), USB_CTRL_SET_TIMEOUT);
-
-	kfree(buf);
-
-	return ret;
-}
-
-static int dlfb_parse_vendor_descriptor(struct dlfb_data *dlfb,
-					struct usb_interface *intf)
-{
-	char *desc;
-	char *buf;
-	char *desc_end;
-	int total_len;
-
-	buf = kzalloc(MAX_VENDOR_DESCRIPTOR_SIZE, GFP_KERNEL);
-	if (!buf)
-		return false;
-	desc = buf;
-
-	total_len = usb_get_descriptor(interface_to_usbdev(intf),
-					0x5f, /* vendor specific */
-					0, desc, MAX_VENDOR_DESCRIPTOR_SIZE);
-
-	/* if not found, look in configuration descriptor */
-	if (total_len < 0) {
-		if (0 == usb_get_extra_descriptor(intf->cur_altsetting,
-			0x5f, &desc))
-			total_len = (int) desc[0];
-	}
-
-	if (total_len > 5) {
-		dev_info(&intf->dev,
-			 "vendor descriptor length: %d data: %11ph\n",
-			 total_len, desc);
-
-		if ((desc[0] != total_len) || /* descriptor length */
-		    (desc[1] != 0x5f) ||   /* vendor descriptor type */
-		    (desc[2] != 0x01) ||   /* version (2 bytes) */
-		    (desc[3] != 0x00) ||
-		    (desc[4] != total_len - 2)) /* length after type */
-			goto unrecognized;
-
-		desc_end = desc + total_len;
-		desc += 5; /* the fixed header we've already parsed */
-
-		while (desc < desc_end) {
-			u8 length;
-			u16 key;
-
-			key = *desc++;
-			key |= (u16)*desc++ << 8;
-			length = *desc++;
-
-			switch (key) {
-			case 0x0200: { /* max_area */
-				u32 max_area = *desc++;
-				max_area |= (u32)*desc++ << 8;
-				max_area |= (u32)*desc++ << 16;
-				max_area |= (u32)*desc++ << 24;
-				dev_warn(&intf->dev,
-					 "DL chip limited to %d pixel modes\n",
-					 max_area);
-				dlfb->sku_pixel_limit = max_area;
-				break;
-			}
-			default:
-				break;
-			}
-			desc += length;
-		}
-	} else {
-		dev_info(&intf->dev, "vendor descriptor not available (%d)\n",
-			 total_len);
-	}
-
-	goto success;
-
-unrecognized:
-	/* allow udlfb to load for now even if firmware unrecognized */
-	dev_err(&intf->dev, "Unrecognized vendor firmware descriptor\n");
-
-success:
-	kfree(buf);
-	return true;
-}
-
-static int dlfb_usb_probe(struct usb_interface *intf,
-			  const struct usb_device_id *id)
-{
-	int i;
-	const struct device_attribute *attr;
-	struct dlfb_data *dlfb;
-	struct fb_info *info;
-	int retval = -ENOMEM;
-	struct usb_device *usbdev = interface_to_usbdev(intf);
-
-	/* usb initialization */
-	dlfb = kzalloc(sizeof(*dlfb), GFP_KERNEL);
-	if (!dlfb) {
-		dev_err(&intf->dev, "%s: failed to allocate dlfb\n", __func__);
-		return -ENOMEM;
-	}
-
-	INIT_LIST_HEAD(&dlfb->deferred_free);
-
-	dlfb->udev = usb_get_dev(usbdev);
-	usb_set_intfdata(intf, dlfb);
-
-	dev_dbg(&intf->dev, "console enable=%d\n", console);
-	dev_dbg(&intf->dev, "fb_defio enable=%d\n", fb_defio);
-	dev_dbg(&intf->dev, "shadow enable=%d\n", shadow);
-
-	dlfb->sku_pixel_limit = 2048 * 1152; /* default to maximum */
-
-	if (!dlfb_parse_vendor_descriptor(dlfb, intf)) {
-		dev_err(&intf->dev,
-			"firmware not recognized, incompatible device?\n");
-		goto error;
-	}
-
-	if (pixel_limit) {
-		dev_warn(&intf->dev,
-			 "DL chip limit of %d overridden to %d\n",
-			 dlfb->sku_pixel_limit, pixel_limit);
-		dlfb->sku_pixel_limit = pixel_limit;
-	}
-
-
-	/* allocates framebuffer driver structure, not framebuffer memory */
-	info = framebuffer_alloc(0, &dlfb->udev->dev);
-	if (!info)
-		goto error;
-
-	dlfb->info = info;
-	info->par = dlfb;
-	info->pseudo_palette = dlfb->pseudo_palette;
-	dlfb->ops = dlfb_ops;
-	info->fbops = &dlfb->ops;
-
-	mutex_init(&dlfb->render_mutex);
-	dlfb_init_damage(dlfb);
-	spin_lock_init(&dlfb->damage_lock);
-	INIT_WORK(&dlfb->damage_work, dlfb_damage_work);
-
-	INIT_LIST_HEAD(&info->modelist);
-
-	if (!dlfb_alloc_urb_list(dlfb, WRITES_IN_FLIGHT, MAX_TRANSFER)) {
-		retval = -ENOMEM;
-		dev_err(&intf->dev, "unable to allocate urb list\n");
-		goto error;
-	}
-
-	/* We don't register a new USB class. Our client interface is dlfbev */
-
-	retval = fb_alloc_cmap(&info->cmap, 256, 0);
-	if (retval < 0) {
-		dev_err(info->device, "cmap allocation failed: %d\n", retval);
-		goto error;
-	}
-
-	retval = dlfb_setup_modes(dlfb, info, NULL, 0);
-	if (retval != 0) {
-		dev_err(info->device,
-			"unable to find common mode for display and adapter\n");
-		goto error;
-	}
-
-	/* ready to begin using device */
-
-	atomic_set(&dlfb->usb_active, 1);
-	dlfb_select_std_channel(dlfb);
-
-	dlfb_ops_check_var(&info->var, info);
-	retval = dlfb_ops_set_par(info);
-	if (retval)
-		goto error;
-
-	retval = register_framebuffer(info);
-	if (retval < 0) {
-		dev_err(info->device, "unable to register framebuffer: %d\n",
-			retval);
-		goto error;
-	}
-
-	for (i = 0; i < ARRAY_SIZE(fb_device_attrs); i++) {
-		attr = &fb_device_attrs[i];
-		retval = device_create_file(info->dev, attr);
-		if (retval)
-			dev_warn(info->device,
-				 "failed to create '%s' attribute: %d\n",
-				 attr->attr.name, retval);
-	}
-
-	retval = device_create_bin_file(info->dev, &edid_attr);
-	if (retval)
-		dev_warn(info->device, "failed to create '%s' attribute: %d\n",
-			 edid_attr.attr.name, retval);
-
-	dev_info(info->device,
-		 "%s is DisplayLink USB device (%dx%d, %dK framebuffer memory)\n",
-		 dev_name(info->dev), info->var.xres, info->var.yres,
-		 ((dlfb->backing_buffer) ?
-		 info->fix.smem_len * 2 : info->fix.smem_len) >> 10);
-	return 0;
-
-error:
-	if (dlfb->info) {
-		dlfb_ops_destroy(dlfb->info);
-	} else {
-		usb_put_dev(dlfb->udev);
-		kfree(dlfb);
-	}
-	return retval;
-}
-
-static void dlfb_usb_disconnect(struct usb_interface *intf)
-{
-	struct dlfb_data *dlfb;
-	struct fb_info *info;
-	int i;
-
-	dlfb = usb_get_intfdata(intf);
-	info = dlfb->info;
-
-	dev_dbg(&intf->dev, "USB disconnect starting\n");
-
-	/* we virtualize until all fb clients release. Then we free */
-	dlfb->virtualized = true;
-
-	/* When non-active we'll update virtual framebuffer, but no new urbs */
-	atomic_set(&dlfb->usb_active, 0);
-
-	/* this function will wait for all in-flight urbs to complete */
-	dlfb_free_urb_list(dlfb);
-
-	/* remove udlfb's sysfs interfaces */
-	for (i = 0; i < ARRAY_SIZE(fb_device_attrs); i++)
-		device_remove_file(info->dev, &fb_device_attrs[i]);
-	device_remove_bin_file(info->dev, &edid_attr);
-
-	unregister_framebuffer(info);
-}
-
-static struct usb_driver dlfb_driver = {
-	.name = "udlfb",
-	.probe = dlfb_usb_probe,
-	.disconnect = dlfb_usb_disconnect,
-	.id_table = id_table,
-};
-
-module_usb_driver(dlfb_driver);
-
-static void dlfb_urb_completion(struct urb *urb)
-{
-	struct urb_node *unode = urb->context;
-	struct dlfb_data *dlfb = unode->dlfb;
-	unsigned long flags;
-
-	switch (urb->status) {
-	case 0:
-		/* success */
-		break;
-	case -ECONNRESET:
-	case -ENOENT:
-	case -ESHUTDOWN:
-		/* sync/async unlink faults aren't errors */
-		break;
-	default:
-		dev_err(&dlfb->udev->dev,
-			"%s - nonzero write bulk status received: %d\n",
-			__func__, urb->status);
-		atomic_set(&dlfb->lost_pixels, 1);
-		break;
-	}
-
-	urb->transfer_buffer_length = dlfb->urbs.size; /* reset to actual */
-
-	spin_lock_irqsave(&dlfb->urbs.lock, flags);
-	list_add_tail(&unode->entry, &dlfb->urbs.list);
-	dlfb->urbs.available++;
-	spin_unlock_irqrestore(&dlfb->urbs.lock, flags);
-
-	up(&dlfb->urbs.limit_sem);
-}
-
-static void dlfb_free_urb_list(struct dlfb_data *dlfb)
-{
-	int count = dlfb->urbs.count;
-	struct list_head *node;
-	struct urb_node *unode;
-	struct urb *urb;
-
-	/* keep waiting and freeing, until we've got 'em all */
-	while (count--) {
-		down(&dlfb->urbs.limit_sem);
-
-		spin_lock_irq(&dlfb->urbs.lock);
-
-		node = dlfb->urbs.list.next; /* have reserved one with sem */
-		list_del_init(node);
-
-		spin_unlock_irq(&dlfb->urbs.lock);
-
-		unode = list_entry(node, struct urb_node, entry);
-		urb = unode->urb;
-
-		/* Free each separately allocated piece */
-		usb_free_coherent(urb->dev, dlfb->urbs.size,
-				  urb->transfer_buffer, urb->transfer_dma);
-		usb_free_urb(urb);
-		kfree(node);
-	}
-
-	dlfb->urbs.count = 0;
-}
-
-static int dlfb_alloc_urb_list(struct dlfb_data *dlfb, int count, size_t size)
-{
-	struct urb *urb;
-	struct urb_node *unode;
-	char *buf;
-	size_t wanted_size = count * size;
-
-	spin_lock_init(&dlfb->urbs.lock);
-
-retry:
-	dlfb->urbs.size = size;
-	INIT_LIST_HEAD(&dlfb->urbs.list);
-
-	sema_init(&dlfb->urbs.limit_sem, 0);
-	dlfb->urbs.count = 0;
-	dlfb->urbs.available = 0;
-
-	while (dlfb->urbs.count * size < wanted_size) {
-		unode = kzalloc(sizeof(*unode), GFP_KERNEL);
-		if (!unode)
-			break;
-		unode->dlfb = dlfb;
-
-		urb = usb_alloc_urb(0, GFP_KERNEL);
-		if (!urb) {
-			kfree(unode);
-			break;
-		}
-		unode->urb = urb;
-
-		buf = usb_alloc_coherent(dlfb->udev, size, GFP_KERNEL,
-					 &urb->transfer_dma);
-		if (!buf) {
-			kfree(unode);
-			usb_free_urb(urb);
-			if (size > PAGE_SIZE) {
-				size /= 2;
-				dlfb_free_urb_list(dlfb);
-				goto retry;
-			}
-			break;
-		}
-
-		/* urb->transfer_buffer_length set to actual before submit */
-		usb_fill_bulk_urb(urb, dlfb->udev, usb_sndbulkpipe(dlfb->udev, 1),
-			buf, size, dlfb_urb_completion, unode);
-		urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
-
-		list_add_tail(&unode->entry, &dlfb->urbs.list);
-
-		up(&dlfb->urbs.limit_sem);
-		dlfb->urbs.count++;
-		dlfb->urbs.available++;
-	}
-
-	return dlfb->urbs.count;
-}
-
-static struct urb *dlfb_get_urb(struct dlfb_data *dlfb)
-{
-	int ret;
-	struct list_head *entry;
-	struct urb_node *unode;
-
-	/* Wait for an in-flight buffer to complete and get re-queued */
-	ret = down_timeout(&dlfb->urbs.limit_sem, GET_URB_TIMEOUT);
-	if (ret) {
-		atomic_set(&dlfb->lost_pixels, 1);
-		dev_warn(&dlfb->udev->dev,
-			 "wait for urb interrupted: %d available: %d\n",
-			 ret, dlfb->urbs.available);
-		return NULL;
-	}
-
-	spin_lock_irq(&dlfb->urbs.lock);
-
-	BUG_ON(list_empty(&dlfb->urbs.list)); /* reserved one with limit_sem */
-	entry = dlfb->urbs.list.next;
-	list_del_init(entry);
-	dlfb->urbs.available--;
-
-	spin_unlock_irq(&dlfb->urbs.lock);
-
-	unode = list_entry(entry, struct urb_node, entry);
-	return unode->urb;
-}
-
-static int dlfb_submit_urb(struct dlfb_data *dlfb, struct urb *urb, size_t len)
-{
-	int ret;
-
-	BUG_ON(len > dlfb->urbs.size);
-
-	urb->transfer_buffer_length = len; /* set to actual payload len */
-	ret = usb_submit_urb(urb, GFP_KERNEL);
-	if (ret) {
-		dlfb_urb_completion(urb); /* because no one else will */
-		atomic_set(&dlfb->lost_pixels, 1);
-		dev_err(&dlfb->udev->dev, "submit urb error: %d\n", ret);
-	}
-	return ret;
-}
-
-module_param(console, bool, S_IWUSR | S_IRUSR | S_IWGRP | S_IRGRP);
-MODULE_PARM_DESC(console, "Allow fbcon to open framebuffer");
-
-module_param(fb_defio, bool, S_IWUSR | S_IRUSR | S_IWGRP | S_IRGRP);
-MODULE_PARM_DESC(fb_defio, "Page fault detection of mmap writes");
-
-module_param(shadow, bool, S_IWUSR | S_IRUSR | S_IWGRP | S_IRGRP);
-MODULE_PARM_DESC(shadow, "Shadow vid mem. Disable to save mem but lose perf");
-
-module_param(pixel_limit, int, S_IWUSR | S_IRUSR | S_IWGRP | S_IRGRP);
-MODULE_PARM_DESC(pixel_limit, "Force limit on max mode (in x*y pixels)");
-
-MODULE_AUTHOR("Roberto De Ioris <roberto@unbit.it>, "
-	      "Jaya Kumar <jayakumar.lkml@gmail.com>, "
-	      "Bernie Thompson <bernie@plugable.com>");
-MODULE_DESCRIPTION("DisplayLink kernel framebuffer driver");
-MODULE_LICENSE("GPL");
-