From: Johan Hovold <johan@kernel.org>
Date: Mon, 25 Aug 2014 17:51:27 +0200
Subject: [PATCH] USB: quirks: enable device-qualifier quirk for Elan
 Touchscreen

Enable device-qualifier quirk for Elan Touchscreen, which often fails to
handle requests for the device_descriptor.

Note that the device sometimes do respond properly with a Request Error
(three times as USB core retries), but usually fails to respond at all.
When this happens any further descriptor requests also fails, for
example:

[ 1528.688934] usb 2-7: new full-speed USB device number 4 using xhci_hcd
[ 1530.945588] usb 2-7: unable to read config index 0 descriptor/start: -71
[ 1530.945592] usb 2-7: can't read configurations, error -71

This has been observed repeating for over a minute before eventual
successful enumeration.

Reported-by: Drew Von Spreecken <drewvs@gmail.com>
Reported-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/usb/core/quirks.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/usb/core/quirks.c b/drivers/usb/core/quirks.c
index 814e712655e4..5ae883dc21f5 100644
--- a/drivers/usb/core/quirks.c
+++ b/drivers/usb/core/quirks.c
@@ -93,6 +93,10 @@ static const struct usb_device_id usb_quirk_list[] = {
 	{ USB_DEVICE(0x04e8, 0x6601), .driver_info =
 			USB_QUIRK_CONFIG_INTF_STRINGS },
 
+	/* Elan Touchscreen */
+	{ USB_DEVICE(0x04f3, 0x0089), .driver_info =
+			USB_QUIRK_DEVICE_QUALIFIER },
+
 	/* Roland SC-8820 */
 	{ USB_DEVICE(0x0582, 0x0007), .driver_info = USB_QUIRK_RESET_RESUME },
 
-- 
1.9.3