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 (file)
--- 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
index 55a17b1..ffe565c 100644 (file)
--- 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 */