[PATCH 3.16 073/192] Add USB quirk for HVR-950q to avoid intermittent device resets

[Ben Hutchings]

3.16.49-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Devin Heitmueller <dheitmueller@xxxxxxxxxxxxxx>

commit 6836796de4019944f4ba4c99a360e8250fd2e735 upstream.

The USB core and sysfs will attempt to enumerate certain parameters
which are unsupported by the au0828 - causing inconsistent behavior
and sometimes causing the chip to reset.  Avoid making these calls.

This problem manifested as intermittent cases where the au8522 would
be reset on analog video startup, in particular when starting up ALSA
audio streaming in parallel - the sysfs entries created by
snd-usb-audio on streaming startup would result in unsupported control
messages being sent during tuning which would put the chip into an
unknown state.

Signed-off-by: Devin Heitmueller <dheitmueller@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 drivers/usb/core/quirks.c | 4 ++++
 1 file changed, 4 insertions(+)

--- a/drivers/usb/core/quirks.c
+++ b/drivers/usb/core/quirks.c
@@ -220,6 +220,10 @@ static const struct usb_device_id usb_qu
 	/* Blackmagic Design UltraStudio SDI */
 	{ USB_DEVICE(0x1edb, 0xbd4f), .driver_info = USB_QUIRK_NO_LPM },
 
+	/* Hauppauge HVR-950q */
+	{ USB_DEVICE(0x2040, 0x7200), .driver_info =
+			USB_QUIRK_CONFIG_INTF_STRINGS },
+
 	/* INTEL VALUE SSD */
 	{ USB_DEVICE(0x8086, 0xf1a5), .driver_info = USB_QUIRK_RESET_RESUME },