This is a note to let you know that I've just added the patch titled

    uas: Disable uas on ASM1051 devices

to the 3.16-stable tree which can be found at:
    
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     uas-disable-uas-on-asm1051-devices.patch
and it can be found in the queue-3.16 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.


>From a9c54caa456dccba938005f6479892b589975e6a Mon Sep 17 00:00:00 2001
From: Hans de Goede <[email protected]>
Date: Wed, 10 Sep 2014 10:51:36 +0200
Subject: uas: Disable uas on ASM1051 devices

From: Hans de Goede <[email protected]>

commit a9c54caa456dccba938005f6479892b589975e6a upstream.

There are a large numbers of issues with ASM1051 devices in uas mode:

1) They do not support REPORT SUPPORTED OPERATION CODES

2) They use out of spec 8 byte status iu-s when they have no sense data,
   switching to normal 16 byte status iu-s when they do have sense data.

3) They hang / crash when combined with some disks, e.g. a Crucial M500 ssd.

4) They hang / crash when stressed (through e.g. sg_reset --bus) with disks
   with which then normally do work (once 1 & 2 are worked around).

Where as in BOT mode they appear to work fine, so the best way forward with
these devices is to just blacklist them for uas usage.

Unfortunately this is easier said then done. as older versions of the ASM1053
(which works fine) use the same usb-id as the ASM1051.

When connected over USB-3 the 2 can be told apart by the number of streams
they support. So this patch adds some less then pretty code to disable uas for
the ASM1051. When connected over USB-2, simply disable uas alltogether for
devices with the shared usb-id.

Cc: [email protected] # 3.16
Signed-off-by: Hans de Goede <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

---
 drivers/usb/storage/uas-detect.h |   27 +++++++++++++++++++++++----
 1 file changed, 23 insertions(+), 4 deletions(-)

--- a/drivers/usb/storage/uas-detect.h
+++ b/drivers/usb/storage/uas-detect.h
@@ -59,10 +59,6 @@ static int uas_use_uas_driver(struct usb
        unsigned long flags = id->driver_info;
        int r, alt;
 
-       usb_stor_adjust_quirks(udev, &flags);
-
-       if (flags & US_FL_IGNORE_UAS)
-               return 0;
 
        alt = uas_find_uas_alt_setting(intf);
        if (alt < 0)
@@ -72,6 +68,29 @@ static int uas_use_uas_driver(struct usb
        if (r < 0)
                return 0;
 
+       /*
+        * ASM1051 and older ASM1053 devices have the same usb-id, and UAS is
+        * broken on the ASM1051, use the number of streams to differentiate.
+        * New ASM1053-s also support 32 streams, but have a different prod-id.
+        */
+       if (udev->descriptor.idVendor == 0x174c &&
+                       udev->descriptor.idProduct == 0x55aa) {
+               if (udev->speed < USB_SPEED_SUPER) {
+                       /* No streams info, assume ASM1051 */
+                       flags |= US_FL_IGNORE_UAS;
+               } else if (usb_ss_max_streams(&eps[1]->ss_ep_comp) == 32) {
+                       flags |= US_FL_IGNORE_UAS;
+               }
+       }
+
+       usb_stor_adjust_quirks(udev, &flags);
+
+       if (flags & US_FL_IGNORE_UAS) {
+               dev_warn(&udev->dev,
+                       "UAS is blacklisted for this device, using usb-storage 
instead\n");
+               return 0;
+       }
+
        if (udev->bus->sg_tablesize == 0) {
                dev_warn(&udev->dev,
                        "The driver for the USB controller %s does not support 
scatter-gather which is\n",


Patches currently in stable-queue which might be from [email protected] are

queue-3.16/uas-disable-uas-on-asm1051-devices.patch
queue-3.16/uas-add-missing-le16_to_cpu-calls-to-asm1051-asm1053-usb-id-check.patch
queue-3.16/uas-log-a-warning-when-we-cannot-use-uas-because-the-hcd-lacks-streams.patch
queue-3.16/uas-only-complain-about-missing-sg-if-all-other-checks-succeed.patch
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to