From: Hans de Goede <hdegoede@redhat.com>
Date: Fri, 1 Aug 2014 15:33:08 +0000 (+0200)
Subject: uas: Limit qdepth to 32 when connected over usb-2
X-Git-Tag: firefly_0821_release~176^2~3489^2~6
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=e2875c33787ebda21aeecc1a9d3ff52b3aa413ec;p=firefly-linux-kernel-4.4.55.git

uas: Limit qdepth to 32 when connected over usb-2

Some jmicron uas chipsets act up (they disconnect from the bus) when sending
more then 32 commands to them at once.

Rather then building an ever growing list with usb-id based quirks for
devices using this chipset, simply reduce the qdepth to 32 when connected
over usb-2. 32 should be plenty to keep things close to maximum
possible throughput on usb-2.

Cc: stable@vger.kernel.org
Tested-and-reported-by: Laszlo T. <tlacix@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/usb/storage/uas.c b/drivers/usb/storage/uas.c
index 511b22953167..3f42785f653c 100644
--- a/drivers/usb/storage/uas.c
+++ b/drivers/usb/storage/uas.c
@@ -1026,7 +1026,7 @@ static int uas_configure_endpoints(struct uas_dev_info *devinfo)
 					    usb_endpoint_num(&eps[3]->desc));
 
 	if (udev->speed != USB_SPEED_SUPER) {
-		devinfo->qdepth = 256;
+		devinfo->qdepth = 32;
 		devinfo->use_streams = 0;
 	} else {
 		devinfo->qdepth = usb_alloc_streams(devinfo->intf, eps + 1,