On Mon, 18 Apr 2005, Grant Grundler wrote: > Alan, (et al) > > Some follow up with the HP r707 and a new workaround. > > First the good news: starting about 2.6.10 I could mount /dev/sda1 > and run my scripts to rsync images off the HP r707 camera. > > Bad news is most of the images would be corrupted with what looked > like missing blocks. I can provide some examples if interested. > (probably got some console output that I didn't save - sorry). > > I could dd the entire /dev/sda1 to a file and then loopback > mount the file to "unload" the .jpg files from the "usb disk". > > "dd if=/dev/sda1" stopped working too with 2.6.11. > I would get bad block errors at the same location: > -rw-r--r-- 1 root root 63275008 Apr 10 22:35 sda1.bad-01 > -rw-r--r-- 1 root root 63275008 Apr 11 08:12 sda1.bad-02
I don't think there were any significant changes to the USB subsystem between 2.6.10 and 2.6.11. At least, not significant enough to cause this. > Workaround was: > # echo "noop" > /sys/block/sda/queue/scheduler > # cat /sys/block/sda/queue/scheduler > [noop] anticipatory deadline cfq > # dd if=/dev/sda1 of=/home/sda1.noop-01 > > resulted in: > -rw-r--r-- 1 root root 252947968 Apr 11 08:25 sda1.noop-01 > > But it's not consistent. I'm also getting: > > grundler <517>ls -lrt sda1.noop-0* > -rw-r--r-- 1 root root 252947968 Apr 11 08:25 sda1.noop-01 > -rw-r--r-- 1 root root 63275008 Apr 18 00:13 sda1.noop-02 > > when I tried it again today. > Console output in this case is appended. > > > And even with the scheduler [noop] workaround, I can NOT rsync > files from the mounted /dev/sda1 to a local file system. > Any clues what's going on here? It's possible that this is a throughput issue, that the camera can't handle transfers occurring too rapidly. I can't think of any other reason why changing the elevator algorithm should have an effect. I have submitted a couple of patches to try and improve error recovery in usb-storage. You can download them at https://lists.one-eyed-alien.net/pipermail/usb-storage/2005-April/001557.html https://lists.one-eyed-alien.net/pipermail/usb-storage/2005-April/001558.html I think they will apply okay to 2.6.12-rc2. Maybe they will help; other prople have reported improvements when using them. Alan Stern ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click _______________________________________________ [email protected] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-users
