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From: Johan Hovold <johan@kernel.org>
Date: Mon, 25 Aug 2014 17:51:26 +0200
Subject: [PATCH] USB: core: add device-qualifier quirk
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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>
---
 drivers/usb/core/hub.c     | 3 +++
 include/linux/usb/quirks.h | 3 +++
 2 files changed, 6 insertions(+)

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 88647f158ed2..d3e4c73d56a2 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -4540,6 +4540,9 @@ 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 32e0f5c04e72..a4abaeb3fb00 100644
--- a/include/linux/usb/quirks.h
+++ b/include/linux/usb/quirks.h
@@ -41,6 +41,9 @@
  */
 #define USB_QUIRK_LINEAR_UFRAME_INTR_BINTERVAL	0x00000080
 
+/* device can't handle device_qualifier descriptor requests */
+#define USB_QUIRK_DEVICE_QUALIFIER	0x00000100
+
 /* device generates spurious wakeup, ignore remote wakeup capability */
 #define USB_QUIRK_IGNORE_REMOTE_WAKEUP	0x00000200
 
-- 
1.9.3