From e2875c33787ebda21aeecc1a9d3ff52b3aa413ec Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Fri, 1 Aug 2014 17:33:08 +0200 Subject: 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. Signed-off-by: Hans de Goede Signed-off-by: Greg Kroah-Hartman --- drivers/usb/storage/uas.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/usb/storage/uas.c') 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, -- cgit v1.2.3 From 2c2d831c81ec75a7b0d8e28caa8e3d9c1fe546f9 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 3 Oct 2014 01:47:09 -0700 Subject: [SCSI] uas: disable use of blk-mq I/O path The uas driver uses the block layer tag for USB3 stream IDs. With blk-mq we can get larger tag numbers that the queue depth, which breaks this assumption. A fix is under way for 3.18, but sits on top of large changes so can't easily be backported. Set the disable_blk_mq path so that a uas device can't easily crash the system when using blk-mq for SCSI. Signed-off-by: Christoph Hellwig Acked-by: Hans de Goede Signed-off-by: James Bottomley --- drivers/usb/storage/uas.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'drivers/usb/storage/uas.c') diff --git a/drivers/usb/storage/uas.c b/drivers/usb/storage/uas.c index 3f42785f653c..9bfa7252f7f9 100644 --- a/drivers/usb/storage/uas.c +++ b/drivers/usb/storage/uas.c @@ -970,6 +970,13 @@ static struct scsi_host_template uas_host_template = { .cmd_per_lun = 1, /* until we override it */ .skip_settle_delay = 1, .ordered_tag = 1, + + /* + * The uas drivers expects tags not to be bigger than the maximum + * per-device queue depth, which is not true with the blk-mq tag + * allocator. + */ + .disable_blk_mq = true, }; #define UNUSUAL_DEV(id_vendor, id_product, bcdDeviceMin, bcdDeviceMax, \ -- cgit v1.2.3