USB: core: add device-qualifier quirk

Add new quirk for devices that cannot handle requests for the device_qualifier descriptor. A USB-2.0 compliant device must respond to requests for the device_qualifier descriptor (even if it's with a request error), but at least one device is known to misbehave after such a request. Suggested-by: Bjørn Mork <bjorn@mork.no> Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mariux64 · Sep 24, 2014 · 2a15938 · 2a15938
1 parent bf17eba
commit 2a15938
Show file tree

Hide file tree

Showing 2 changed files with 6 additions and 0 deletions.
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
@@ -4538,6 +4538,9 @@ check_highspeed (struct usb_hub *hub, struct usb_device *udev, int port1)
 	struct usb_qualifier_descriptor	*qual;
 	int				status;
 
+	if (udev->quirks & USB_QUIRK_DEVICE_QUALIFIER)
+		return;
+
 	qual = kmalloc (sizeof *qual, GFP_KERNEL);
 	if (qual == NULL)
 		return;

diff --git a/include/linux/usb/quirks.h b/include/linux/usb/quirks.h
@@ -41,4 +41,7 @@
  */
 #define USB_QUIRK_LINEAR_UFRAME_INTR_BINTERVAL	0x00000080
 
+/* device can't handle device_qualifier descriptor requests */
+#define USB_QUIRK_DEVICE_QUALIFIER	0x00000100
+
 #endif /* __LINUX_USB_QUIRKS_H */