[Bug 12730] New: USB memory stick moved to different device on error / may be due to problem with high concurrent load on two USB devices

[Bug 12730] New: USB memory stick moved to different device on error / may be due to problem with high concurrent load on two USB devices

[bugme-daemon]

http://bugzilla.kernel.org/show_bug.cgi?id=12730

           Summary: USB memory stick moved to different device on error /
                    may be due to problem with high concurrent load on two
                    USB devices
           Product: IO/Storage
           Version: 2.5
     KernelVersion: 2.6.27.17
          Platform: All
        OS/Version: Linux
              Tree: Mainline
            Status: NEW
          Severity: normal
          Priority: P1
         Component: SCSI
        AssignedTo: linux-scsi@vger.kernel.org
        ReportedBy: wagner@tik.ee.ethz.ch


Latest working kernel version: No idea
Earliest failing kernel version: No idea
Distribution: Debian Lenny
Hardware Environment: USB is EHCI by ATI/AMD SB600. CPU is a single core
Sempron LE-1250

Software Environment: dd_rescue and a self-written flash exerciser
Problem Description: I have a 2GB flash as /dev/sdd and a 16GB flash as
/dev/sde. The 2 GB is exercised by a tester that writes and verifies. (This is
intended to be run until there are read errors. I expect that may take up to a
year or longer.) The 16GB I wanted to do a speed test using dd_rescue /dev/sde
/dev/null. It seems this somehow caused a problem leadung to high volume
console output and USB disconnects for both devices (found in the logs). 

I have tried the read from the 16GB without the exerciser running, this seems
to work. Unfortunately I did not find any error diagnotics in the logs besides
the USB disconnect, at least not anythign I recognized. What I did should not
have caused USB disconnects in the first place, so this may also be an USB
driver problem or the like. 

Now the interesting thing is that the kernel seems to have disabled /dev/sdd
and used the 16GB flash as new /dev/sdd. The 2GB flash did not turn up again.
Not good, devices should not change without an explicit re-plug.

If an USB disconnect is indistinguishable in software from a physical unplug
and replug, I understand that nothing can be done. But if it can be
distinguished, devices should be prevented from moving around on error.

Steps to reproduce: I tried to run this again. Just a reading of the 16GB flash
with dd_rescue did not produce any problems. Starting the flash exerciser again
after replugging both flash devices to get them to their original devices
worked. I could not recreate the original situation, since the port with the
2GB device was now only using OHCI and a reboot on this machine causes some
effort. This may therefore also be an USB driver issue with the EHCI driver
being crashy.


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[Bug 12730] USB memory stick moved to different device on error / may be due to problem with high concurrent load on two USB devices

[bugme-daemon]

http://bugzilla.kernel.org/show_bug.cgi?id=12730





------- Comment #1 from wagner@tik.ee.ethz.ch  2009-02-17 14:26 -------
from /var/log/messages. Sorry for the line mangling.

Feb 17 21:04:10 gate kernel: usb 1-1: new high speed USB device using
ehci_hcd and address 4
Feb 17 21:04:10 gate kernel: usb 1-1: configuration #1 chosen from 1 choice
Feb 17 21:04:10 gate kernel: scsi5 : SCSI emulation for USB Mass Storage
devices
Feb 17 21:04:16 gate kernel: scsi 5:0:0:0: Direct-Access     TDKMedia
Trans-It Drive   PMAP PQ: 0 ANSI: 0 CCS
Feb 17 21:04:17 gate kernel: sd 5:0:0:0: [sde] 31260672 512-byte hardware
sectors (16005 MB)
Feb 17 21:04:17 gate kernel: sd 5:0:0:0: [sde] Write Protect is off
Feb 17 21:04:20 gate kernel: sd 5:0:0:0: [sde] 31260672 512-byte hardware
sectors (16005 MB)
Feb 17 21:04:20 gate kernel: sd 5:0:0:0: [sde] Write Protect is off
Feb 17 21:04:20 gate kernel:  sde: sde1
Feb 17 21:04:20 gate kernel: sd 5:0:0:0: [sde] Attached SCSI removable disk
Feb 17 21:04:20 gate kernel: sd 5:0:0:0: Attached scsi generic sg4 type 0
Feb 17 22:07:04 gate kernel: usb 1-1: USB disconnect, address 4
Feb 17 22:07:04 gate kernel: sd 5:0:0:0: [sde] Result: hostbyte=DID_ERROR
driverbyte=DRIVER_OK,SUGGEST_OK
Feb 17 22:07:05 gate last message repeated 9 times
Feb 17 22:07:05 gate kernel: usb 1-2: reset high speed USB device using
ehci_hcd and address 3
Feb 17 22:07:09 gate kernel: __ratelimit: 24335 callbacks suppressed
Feb 17 22:07:10 gate kernel: sd 4:0:0:0: [sdd] Result: hostbyte=DID_ERROR
driverbyte=DRIVER_OK,SUGGEST_OK
Feb 17 22:07:10 gate last message repeated 4 times
Feb 17 22:07:10 gate kernel: usb 1-1: new high speed USB device using
ehci_hcd and address 5
Feb 17 22:07:10 gate kernel: usb 1-1: configuration #1 chosen from 1 choice
Feb 17 22:07:10 gate kernel: scsi6 : SCSI emulation for USB Mass Storage
devices
Feb 17 22:07:10 gate kernel: usb 1-2: USB disconnect, address 3
Feb 17 22:07:14 gate kernel: __ratelimit: 24767 callbacks suppressed
Feb 17 22:07:15 gate kernel: scsi 6:0:0:0: Direct-Access     TDKMedia
Trans-It Drive   PMAP PQ: 0 ANSI: 0 CCS
Feb 17 22:07:15 gate kernel: sd 6:0:0:0: [sdd] 31260672 512-byte hardware
sectors (16005 MB)
Feb 17 22:07:15 gate kernel: sd 6:0:0:0: [sdd] Write Protect is off
Feb 17 22:07:15 gate kernel: sd 6:0:0:0: [sdd] 31260672 512-byte hardware
sectors (16005 MB)
Feb 17 22:07:15 gate kernel: sd 6:0:0:0: [sdd] Write Protect is off
Feb 17 22:07:15 gate kernel:  sdd: unknown partition table
Feb 17 22:07:15 gate kernel: sd 6:0:0:0: [sdd] Attached SCSI removable disk
Feb 17 22:07:15 gate kernel: sd 6:0:0:0: Attached scsi generic sg3 type 0
Feb 17 22:07:19 gate kernel: __ratelimit: 24396 callbacks suppressed
Feb 17 22:07:24 gate kernel: __ratelimit: 23645 callbacks suppressed
Feb 17 22:07:29 gate kernel: __ratelimit: 21585 callbacks suppressed


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[Bug 12730] USB memory stick moved to different device on error / may be due to problem with high concurrent load on two USB devices

[bugme-daemon]

http://bugzilla.kernel.org/show_bug.cgi?id=12730


stern@rowland.harvard.edu changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |stern@rowland.harvard.edu




------- Comment #2 from stern@rowland.harvard.edu  2009-02-18 07:19 -------
Unfortunately, a lot of EHCI hardware seems to have trouble carrying out
transfers over different ports concurrently.

Your log doesn't contain enough information to tell just what happened.  If you
want more information, you can build a kernel with CONFIG_USB_DEBUG enabled. 
There may or may not have been an actual USB disconnect.  (Such an electronic
disconnect is indeed indistinguishable from a physical unplug.)

The log shows that the 1-2 drive got into an error state requiring a reset;
quite possibly the reset failed.  This leaves the kernel no choice but to carry
out a "logical" disconnect.  While it's not exactly the same as a physical
disconnect, it is treated the same way and so it is indistinguishable as far as
most of the kernel is concerned.

It's impossible to tell whether the error state was caused by the drive or by
the EHCI controller.  To find out for certain, you'd have to use a USB bus
analyzer.


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[Bug 12730] USB memory stick moved to different device on error / may be due to problem with high concurrent load on two USB devices

[bugme-daemon]

http://bugzilla.kernel.org/show_bug.cgi?id=12730





------- Comment #3 from wagner@tik.ee.ethz.ch  2009-02-18 10:32 -------
Ok, so this is a known issue with AHCI hardware. I think I till pass on the
debug-kernel. 

Anyways, thanks for the info. I will just be careful with raw access to USB
devices. Mounted ones should not be that critical, since they will not remount
themselves. 


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[Bug 12730] USB memory stick moved to different device on error / may be due to problem with high concurrent load on two USB devices

[bugme-daemon]

http://bugzilla.kernel.org/show_bug.cgi?id=12730





------- Comment #4 from stern@rowland.harvard.edu  2009-03-12 08:55 -------
A patch was accepted recently which just might have some effect on this
problem:

http://www.kernel.org/pub/linux/kernel/people/gregkh/gregkh-2.6/gregkh-04-usb/usb-ehci-add-software-retry-for-transaction-errors.patch


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[Bug 12730] USB memory stick moved to different device on error / may be due to problem with high concurrent load on two USB devices

[bugzilla-daemon]

http://bugzilla.kernel.org/show_bug.cgi?id=12730


Alan <alan@lxorguk.ukuu.org.uk> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
                 CC|                            |alan@lxorguk.ukuu.org.uk
         Resolution|                            |INSUFFICIENT_DATA
         Regression|---                         |No




--- Comment #5 from Alan <alan@lxorguk.ukuu.org.uk>  2010-01-25 14:49:37 ---
Closing old stale bugs

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[Bug 12730] USB memory stick moved to different device on error / may be due to problem with high concurrent load on two USB devices

[bugzilla-daemon]

http://bugzilla.kernel.org/show_bug.cgi?id=12730


Alan <alan@lxorguk.ukuu.org.uk> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |CLOSED




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