USB: core: add device-qualifier quirk

commit 2a159389bf5d962359349a76827b2f683276a1c7 upstream.

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 445d62a..d2bd9d7 100644 (file)
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -4378,6 +4378,9 @@ 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 49587dc..8b96ae2 100644 (file)
--- a/include/linux/usb/quirks.h
+++ b/include/linux/usb/quirks.h
@@ -33,4 +33,7 @@
 /* device generates spurious wakeup, ignore remote wakeup capability */
 #define USB_QUIRK_IGNORE_REMOTE_WAKEUP 0x00000200
 
+/* device can't handle device_qualifier descriptor requests */
+#define USB_QUIRK_DEVICE_QUALIFIER     0x00000100
+
 #endif /* __LINUX_USB_QUIRKS_H */