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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>
Johan Hovold 11 years ago
parent
commit
2a159389bf
2 changed files with 6 additions and 0 deletions
  1. 3 0
      drivers/usb/core/hub.c
  2. 3 0
      include/linux/usb/quirks.h

+ 3 - 0
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;

+ 3 - 0
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 */