diff mbox series

usb: gadget: f_hid: added GET_IDLE and SET_IDLE handlers

Message ID 20210721180351.129450-1-mdevaev@gmail.com
State New
Headers show
Series usb: gadget: f_hid: added GET_IDLE and SET_IDLE handlers | expand

Commit Message

Maxim Devaev July 21, 2021, 6:03 p.m. UTC
The USB HID standard declares mandatory support for GET_IDLE and SET_IDLE
requests for Boot Keyboard. Most hosts can handle their absence, but others
like some old/strange UEFIs and BIOSes consider this a critical error
and refuse to work with f_hid.

This primitive implementation of saving and returning idle is sufficient
to meet the requirements of the standard and these devices.

Signed-off-by: Maxim Devaev <mdevaev@gmail.com>
---
 drivers/usb/gadget/function/f_hid.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

Comments

Felipe Balbi July 22, 2021, 11:49 a.m. UTC | #1
Maxim Devaev <mdevaev@gmail.com> writes:

> The USB HID standard declares mandatory support for GET_IDLE and SET_IDLE

> requests for Boot Keyboard. Most hosts can handle their absence, but others

> like some old/strange UEFIs and BIOSes consider this a critical error

> and refuse to work with f_hid.

>

> This primitive implementation of saving and returning idle is sufficient

> to meet the requirements of the standard and these devices.

>

> Signed-off-by: Maxim Devaev <mdevaev@gmail.com>


yeah, I don't see any issues with this. If you have access to the tool,
mind running USBCV on the f_hid gadget? Would be cool to get some
confirmation that we're within spec.

That shouldn't gate $subject though.

Acked-by: Felipe Balbi <balbi@kernel.org>


-- 
balbi
Maxim Devaev July 22, 2021, 5:51 p.m. UTC | #2
> Felipe Balbi <balbi@kernel.org> writes:

> 

> yeah, I don't see any issues with this. If you have access to the tool,

> mind running USBCV on the f_hid gadget? Would be cool to get some

> confirmation that we're within spec.


Thanks for pointing to USBCV. I used a hardware USB protocol analyzer
to understand what was wrong with f_hid, and my hosts only sent idle=0.
Thanks to the test, I realized that I should only use the upper byte
that contains duration. Here a fixed version of the patch,
which successfully passes all HID tests. The idle part:

    Now Starting Test: HID Class GET/SET Idle Test (Configuration Index 0)
    Start time: Jul 22, 2021 - 20:29:40
    No report IDs found in report descriptor for Interface : 0x0
    GET/SETIdle test for report ID 0. Setting Idle rate to : 0x7F
    No report IDs found in report descriptor for Interface : 0x1
    GET/SETIdle test for report ID 0. Setting Idle rate to : 0x7F
    
    Stop time: Jul 22, 2021 - 20:29:41
    Duration:  1 second.
    Stopping Test [ HID Class GET/SET Idle Test (Configuration Index 0):
         Number of: Fails (0); Aborts (0); Warnings (0) ]


From ac56ddc1ab2dfa599a12a3bf064e520d587e89fe Mon Sep 17 00:00:00 2001
From: Maxim Devaev <mdevaev@gmail.com>

Date: Wed, 21 Jul 2021 20:48:28 +0300
Subject: [PATCH] usb: gadget: f_hid: added GET_IDLE and SET_IDLE handlers

The USB HID standard declares mandatory support for GET_IDLE and SET_IDLE
requests for Boot Keyboard. Most hosts can handle their absence, but others
like some old/strange UEFIs and BIOSes consider this a critical error
and refuse to work with f_hid.

This primitive implementation of saving and returning idle is sufficient
to meet the requirements of the standard and these devices.

Signed-off-by: Maxim Devaev <mdevaev@gmail.com>

---
 drivers/usb/gadget/function/f_hid.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/drivers/usb/gadget/function/f_hid.c b/drivers/usb/gadget/function/f_hid.c
index 02683ac07..1010f0a3e 100644
--- a/drivers/usb/gadget/function/f_hid.c
+++ b/drivers/usb/gadget/function/f_hid.c
@@ -41,6 +41,7 @@ struct f_hidg {
 	unsigned char			bInterfaceSubClass;
 	unsigned char			bInterfaceProtocol;
 	unsigned char			protocol;
+	unsigned char			idle;
 	unsigned short			report_desc_length;
 	char				*report_desc;
 	unsigned short			report_length;
@@ -523,6 +524,14 @@ static int hidg_setup(struct usb_function *f,
 		goto respond;
 		break;
 
+	case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
+		  | HID_REQ_GET_IDLE):
+		VDBG(cdev, "get_idle\n");
+		length = min_t(unsigned int, length, 1);
+		((u8 *) req->buf)[0] = hidg->idle;
+		goto respond;
+		break;
+
 	case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
 		  | HID_REQ_SET_REPORT):
 		VDBG(cdev, "set_report | wLength=%d\n", ctrl->wLength);
@@ -546,6 +555,14 @@ static int hidg_setup(struct usb_function *f,
 		goto stall;
 		break;
 
+	case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
+		  | HID_REQ_SET_IDLE):
+		VDBG(cdev, "set_idle\n");
+		length = 0;
+		hidg->idle = value >> 8;
+		goto respond;
+		break;
+
 	case ((USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_INTERFACE) << 8
 		  | USB_REQ_GET_DESCRIPTOR):
 		switch (value >> 8) {
@@ -773,6 +790,7 @@ static int hidg_bind(struct usb_configuration *c, struct usb_function *f)
 	hidg_interface_desc.bInterfaceSubClass = hidg->bInterfaceSubClass;
 	hidg_interface_desc.bInterfaceProtocol = hidg->bInterfaceProtocol;
 	hidg->protocol = HID_REPORT_PROTOCOL;
+	hidg->idle = 1;
 	hidg_ss_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
 	hidg_ss_in_comp_desc.wBytesPerInterval =
 				cpu_to_le16(hidg->report_length);
-- 
2.32.0
Felipe Balbi July 23, 2021, 7:20 a.m. UTC | #3
Maxim Devaev <mdevaev@gmail.com> writes:

>> Felipe Balbi <balbi@kernel.org> writes:

>> 

>> yeah, I don't see any issues with this. If you have access to the tool,

>> mind running USBCV on the f_hid gadget? Would be cool to get some

>> confirmation that we're within spec.

>

> Thanks for pointing to USBCV. I used a hardware USB protocol analyzer

> to understand what was wrong with f_hid, and my hosts only sent idle=0.

> Thanks to the test, I realized that I should only use the upper byte

> that contains duration. Here a fixed version of the patch,

> which successfully passes all HID tests. The idle part:

>

>     Now Starting Test: HID Class GET/SET Idle Test (Configuration Index 0)

>     Start time: Jul 22, 2021 - 20:29:40

>     No report IDs found in report descriptor for Interface : 0x0

>     GET/SETIdle test for report ID 0. Setting Idle rate to : 0x7F

>     No report IDs found in report descriptor for Interface : 0x1

>     GET/SETIdle test for report ID 0. Setting Idle rate to : 0x7F

>     

>     Stop time: Jul 22, 2021 - 20:29:41

>     Duration:  1 second.

>     Stopping Test [ HID Class GET/SET Idle Test (Configuration Index 0):

>          Number of: Fails (0); Aborts (0); Warnings (0) ]

>

>

> From ac56ddc1ab2dfa599a12a3bf064e520d587e89fe Mon Sep 17 00:00:00 2001

> From: Maxim Devaev <mdevaev@gmail.com>

> Date: Wed, 21 Jul 2021 20:48:28 +0300

> Subject: [PATCH] usb: gadget: f_hid: added GET_IDLE and SET_IDLE handlers

>

> The USB HID standard declares mandatory support for GET_IDLE and SET_IDLE

> requests for Boot Keyboard. Most hosts can handle their absence, but others

> like some old/strange UEFIs and BIOSes consider this a critical error

> and refuse to work with f_hid.

>

> This primitive implementation of saving and returning idle is sufficient

> to meet the requirements of the standard and these devices.

>

> Signed-off-by: Maxim Devaev <mdevaev@gmail.com>


Great, thank you.

Acked-by: Felipe Balbi <balbi@kernel.org>


-- 
balbi
diff mbox series

Patch

diff --git a/drivers/usb/gadget/function/f_hid.c b/drivers/usb/gadget/function/f_hid.c
index 02683ac07..1e1d1ae38 100644
--- a/drivers/usb/gadget/function/f_hid.c
+++ b/drivers/usb/gadget/function/f_hid.c
@@ -41,6 +41,7 @@  struct f_hidg {
 	unsigned char			bInterfaceSubClass;
 	unsigned char			bInterfaceProtocol;
 	unsigned char			protocol;
+	unsigned char			idle;
 	unsigned short			report_desc_length;
 	char				*report_desc;
 	unsigned short			report_length;
@@ -523,6 +524,14 @@  static int hidg_setup(struct usb_function *f,
 		goto respond;
 		break;
 
+	case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
+		  | HID_REQ_GET_IDLE):
+		VDBG(cdev, "get_idle\n");
+		length = min_t(unsigned int, length, 1);
+		((u8 *) req->buf)[0] = hidg->idle;
+		goto respond;
+		break;
+
 	case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
 		  | HID_REQ_SET_REPORT):
 		VDBG(cdev, "set_report | wLength=%d\n", ctrl->wLength);
@@ -546,6 +555,14 @@  static int hidg_setup(struct usb_function *f,
 		goto stall;
 		break;
 
+	case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
+		  | HID_REQ_SET_IDLE):
+		VDBG(cdev, "set_idle\n");
+		length = 0;
+		hidg->idle = value;
+		goto respond;
+		break;
+
 	case ((USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_INTERFACE) << 8
 		  | USB_REQ_GET_DESCRIPTOR):
 		switch (value >> 8) {
@@ -773,6 +790,7 @@  static int hidg_bind(struct usb_configuration *c, struct usb_function *f)
 	hidg_interface_desc.bInterfaceSubClass = hidg->bInterfaceSubClass;
 	hidg_interface_desc.bInterfaceProtocol = hidg->bInterfaceProtocol;
 	hidg->protocol = HID_REPORT_PROTOCOL;
+	hidg->idle = 1;
 	hidg_ss_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
 	hidg_ss_in_comp_desc.wBytesPerInterval =
 				cpu_to_le16(hidg->report_length);