From 198de51dbc3454d95b015ca0a055b673f85f01bb Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Tue, 12 Apr 2016 12:27:08 +0200 Subject: [PATCH] USB: uas: Limit qdepth at the scsi-host level Commit 64d513ac31bd ("scsi: use host wide tags by default") causes the SCSI core to queue more commands then we can handle on devices with multiple LUNs, limit the queue depth at the scsi-host level instead of per slave to fix this. BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=1315013 Cc: stable@vger.kernel.org # 4.4.x and 4.5.x Signed-off-by: Hans de Goede Signed-off-by: Greg Kroah-Hartman --- drivers/usb/storage/uas.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/usb/storage/uas.c b/drivers/usb/storage/uas.c index 13e4cc31bc79..b1ec7499166d 100644 --- a/drivers/usb/storage/uas.c +++ b/drivers/usb/storage/uas.c @@ -824,7 +824,6 @@ static int uas_slave_configure(struct scsi_device *sdev) if (devinfo->flags & US_FL_BROKEN_FUA) sdev->broken_fua = 1; - scsi_change_queue_depth(sdev, devinfo->qdepth - 2); return 0; } @@ -956,6 +955,12 @@ static int uas_probe(struct usb_interface *intf, const struct usb_device_id *id) if (result) goto set_alt0; + /* + * 1 tag is reserved for untagged commands + + * 1 tag to avoid off by one errors in some bridge firmwares + */ + shost->can_queue = devinfo->qdepth - 2; + usb_set_intfdata(intf, shost); result = scsi_add_host(shost, &intf->dev); if (result) -- 2.20.1