On Tuesday 11 July 2006 12:32 pm, Andrew Morton wrote: > Problem Description: > Write errors when large files are transferred; > sometimes no useful error message; > in some cases "reset high speed USB device"; details see below > > I think this is a software problem because: > * the same LaCie DVD writer works under Windows > * the same 1GB USB sticks work under Windows > * various USB 2.0 memory sticks with 128 MB or less work fine
I'm curious ... how does the throughput compare between Linux and Windows? For big blocks; say, what "dd bs=64K" would do. (Preferably measuring read and write speeds without a filesystem in the way.) I don't really have a handle on this and I'm not likely to get one without some quality time with a high speed analyser ... But one theory I've had about this class of errors is that Linux may be driving the device faster than Windows, and thereby hitting races in those devices (hardware or firmware) that Windows wouldn't trigger. > * boot the computer > * connect the DVD writer > * do a "growisofs", get the same error as above > * disconnect the DVD writer and connect it again > * do another "growisofs" > * this one works! I get a DVD burned without any errors. > * further attempts to "growisofs" all fail unless I reboot and follow the > procedure from the beginning That's most bizarre. This drive has an external power adapter, yes? Which means it could retain state unless you power it off ... did you try this experiment both with and without driver power-off? If it works without power-off, and fails with it, that strongly suggests this is a bug in the peripheral. Strongly enough that I'd suggest taking it up with LaCie... > cp: failed to preserve ownership of '/media/usb/<filename>': Operation not > permitted. Strange. USB doesn't issue EPERM in many places ... it'd be easy to rule out (or in!) the USB stack as a factor here. The key spot is in core/hcd.c::hcd_submit_urb() when urb->reject is set, and that should probably change ... it's not a permission error in the security sense intended by EPERM. You might change that to something less generic like EBADRQC, and see if that symptom changes. If it does, that's a solid clue ... - Dave ------------------------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
