On Mon, Dec 09, 2002 at 05:32:02PM -0800, David Brownell wrote: > Greg KH wrote: > >On Mon, Dec 09, 2002 at 03:39:37PM -0800, Greg KH wrote: > > > >>Hm, running Linus's latest bk tree with the USB patches results in some > >>usb-storage errors causing timeouts: > > Was this a high speed disk, or a full speed one using a TT?
High speed. I finally got a USB 2.0 hub, but wasn't using it. Full speed on the same box, same kernel, using uhci-hcd works just fine. > >>... > >>Dec 9 15:22:26 soap kernel: usb-storage: > >>usb_stor_bulk_transfer_sglist(): xfer 65536 bytes, 16 entries > >>Dec 9 15:22:26 soap kernel: usb-storage: Status code -121; transferred > >>65037/65536 > >>Dec 9 15:22:26 soap kernel: usb-storage: -- unknown error > > That's not a timeout, "-EREMOTEIO" means it got a short read. > In this case, that last packet included only 13 bytes not 512. > (Assuming this was at high speed, otherwise it wasn't the last > one, and that was likely 13 bytes out of 64.) Yeah, that suggests that either usb-storage needs to handle this somehow, right? > Given there's only one place in the EHCI driver where EREMOTEIO > shows up, I'm tempted to believe that the hardware really did > return a short read in that last packet. > > As for why it did so, no ideas just now. Though I wonder if > maybe retrying short reads wouldn't help, on the premise that > the disk had a temporary "can't keep up" problem, since using > those scatterlist operations drives that hardware much faster > than it was ever driven by earlier kernels. But does that deserve the long "reset the endpoint" delay that happens because of this? I'd rather have a bit slower throughput and no long delays, than shorter bursts of data, with long delays, cutting the end throughput way down. thanks, greg k-h ------------------------------------------------------- This sf.net email is sponsored by:ThinkGeek Welcome to geek heaven. http://thinkgeek.com/sf _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
