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>
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index d481c99..c01b724 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -4538,6 +4538,9 @@
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
index 55a17b1..ffe565c 100644
--- 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 */