diff mbox series

Revert "usb: gadget: composite: fix OS descriptors w_value

Message ID AS8PR05MB84851190CC1941157ED33D7D909C2@AS8PR05MB8485.eurprd05.prod.outlook.com
State New
Headers show
Series Revert "usb: gadget: composite: fix OS descriptors w_value | expand

Commit Message

Vrastil, Michal Sept. 4, 2024, 3:01 p.m. UTC 
This reverts commit ec6ce7075ef879b91a8710829016005dc8170f17.

Fix install of WinUSB dsriver using OS descriptors.
Without the fix the drivers is not installed correctly
and the property 'DeviceInterfaceGUID' is missing on host side.

The original change was based on assumption that the interface number
is in the high byte of wValue but it is in the low byte, instead.
Unfortunately, the fix is based on MS documentation which is also wrong.

The actual USB request for OS descriptors (using USB analyzer) looks
like:

Offset  0   1   2   3   4   5   6   7
0x000   C1  A1  02  00  05  00  0A  00

C1: bmRequestType (device to host, vendor, interface)
A1: nas magic number
0002: wValue (2: nas interface)
0005: wIndex (5: get extended property i.e. nas interface GUID)
008E: wLength (142)

The fix was tested on Windows 10 and Windows 11.

Fixes: ec6ce70 ("usb: gadget: composite: fix OS descriptors w_value logic")
Signed-off-by: Michal Vrastil <michal.vrastil@hidglobal.com>
---
 drivers/usb/gadget/composite.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
index 17ae3b394469..a3106b179562 100644
--- a/drivers/usb/gadget/composite.c
+++ b/drivers/usb/gadget/composite.c
@@ -1925,7 +1925,7 @@  composite_setup(struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
 			buf[5] = 0x01;
 			switch (ctrl->bRequestType & USB_RECIP_MASK) {
 			case USB_RECIP_DEVICE:
-				if (w_index != 0x4 || (w_value & 0xff))
+				if (w_index != 0x4 || (w_value >> 8))
 					break;
 				buf[6] = w_index;
 				/* Number of ext compat interfaces */
@@ -1941,9 +1941,9 @@  composite_setup(struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
 				}
 				break;
 			case USB_RECIP_INTERFACE:
-				if (w_index != 0x5 || (w_value & 0xff))
+				if (w_index != 0x5 || (w_value >> 8))
 					break;
-				interface = w_value >> 8;
+				interface = w_value & 0xFF;
 				if (interface >= MAX_CONFIG_INTERFACES ||
 				    !os_desc_cfg->interface[interface])
 					break;