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 511b229..3f42785 100644 (file)
--- 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,