RE: [BUG: multiple kernels] data corruption while reading from anUSB2 connected HD

[Emiliano Garcia]

Hello Everyone,
 
    I can confirm I am also experiencing problems with usb-storage on 
usb 2.0 devices. I have two separate usb 2.0 drives, one with the oxford 
911 usb/firewire chipset and another with a gensys chip. Anyhow, I tar 
up my servers once a week and copy the bzipped tar to my usb hard drive. 
I have found now that I cannot extract the tar.bz2 files due to crc 
errors. When I run bzip2 -tvv on the original archive on the server, it 
passes without failure. When I run the test (bzip2 -tvv) on the copy of 
the archive on the usb 2.0 disks, it says they have crc errors. dmesg 
does not show anything exciting besides the mounting/detection of the 
drives. Please help!

Thanks to all of you for you hard work.

Emiliano Garcia


   * /To/: linux-kernel@xxxxxxxxxxxxxxx
     <mailto:linux-kernel%40vger.kernel.org>
   * /Subject/: [BUG: multiple kernels] data corruption while reading
     from an USB2 connected HD
   * /From/: Hajo Simons <simons@xxxxxxxxxxxxx
     <mailto:simons%40dc-systeme.de>>
   * /Date/: Mon, 27 Sep 2004 11:06:06 +0200
   * /Cc/: hsimons@xxxxxx <mailto:hsimons%40gmx.de>
   * /Organization/: dc-Systeme
   * /Sender/: linux-kernel-owner@xxxxxxxxxxxxxxx
     <mailto:linux-kernel-owner%40vger.kernel.org>
   * /User-agent/: KMail/1.7

------------------------------------------------------------------------

usb-storage sporadically loses data while reading

In a data stream of 20M about 10 bytes get lost averagely while reading from a 
HD connected via USB 2.0 which practically means that most files stored on 
that HD show different md5 fingerprints if the IO read buffer was flushed 
meanwhile.

keywords:
usb-storage, external Disk, USB 2.0, data corruption while reading

data get lost while reading on:
2.4.27
2.6.8.1
2.6.8-gentoo-r3
2.6.8-gentoo-r4 preemptive/non-preemptive
2.6.9-rc1

whereas no faults are seen on: 
Windows XP SP1 (without specific drivers for that USB2 disk device) 

system:
Barton 3.2 200
Asus A7N8XX (nforce2) FSB at 192MHz, CPU at FSB*11.5
(A7N8* or CPU (don't know) cannot run stable for over a week at 200MHz FSB)
1G 400MHz DDR RAM (tested) runnung at FSB Speed
2 IDE disks connected to the onboard nforce2 IDE controller
1 IDE disk USB2ish connected to ALi (ID 0402:5621 ALi Corp.) via onboard 
nforce2 USB controller

test: 
(UAHD: usb attached HD)
create a big file on a UAHD, say 20M
md5sum it
umount UAHD
remount it
md5sum that file again
chances are 50/50, that you get a different number
if md5sums are equal, repeat the procedure

( did the same test on that mentioned WinXP: everything ok;
  and yes, I did unplug the device between the reads )

note:
system behaves rock-solid besides that issue
tried blk_queue_max_sectors(sdev->request_queue, 1) in 
scsiglue.c:slave_configure() to no avail
tried PREEMPTIVE on/off, same


details:


....
snip

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/