On Thu, 23 Mar 2006, Oliver Neukum wrote: > Am Donnerstag, 23. März 2006 23:12 schrieb Alisdair Davey: > > Currently all I need to do is make sure I can get out a single image we > > can look at. A single image consists of 2097152 bytes. If I run the > > userspace program with the machine in single user mode I seem to be able > > to do this [I've yet to confirm what I'm pulling off is an image as > > opposed to empty bytes!]. However when I boot it to multiuser mode, the > > system dies. Primarily it starts by hanging all the X-window stuff but > > eventually everythig grinds to a halt. There doesn't seem to be anything > > in the kernel log though. I've traced the problem to the raise_read > > subroutine at the point at which I use usb_bulk_msg to get the data. I'm > > obviously missing something and I frankly don't know what. > > You should not use usb_bulk_msg() to transfer 500K in one go. > Use a reasonable buffer, eg. 16K, and several URBs.
In addition, you cannot allocate a USB transfer buffer using vmalloc(). You must use kmalloc() or an equivalent routine. Alan Stern ------------------------------------------------------- This SF.Net email is sponsored by xPML, a groundbreaking scripting language that extends applications into web and mobile media. Attend the live webcast and join the prime developer group breaking into this new coding territory! http://sel.as-us.falkag.net/sel?cmd=lnk&kid=110944&bid=241720&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
