On Sun, Nov 04, 2001 at 12:41:10PM -0500, Johannes Erdfelt wrote: > On Sun, Nov 04, 2001, Marcus Meissner <[EMAIL PROTECTED]> wrote: > > I have started doing a gphoto2 port of the Mustek MDC 800 driver. > > > > Everything looks good, except that the userspace USB stuff is acting > > flaky when reading from the INTERRUPT Endpoint. While gets the 'camera busy' > > and 'camera ready' packets just fine, and sometimes also the data packets, > > it sometimes appears to skip datapackets coming from the Interrupt Endpoint. > > > > I had a deeper look at the whole thing and it appears that libusb 0.1.4 > > reads data always using the Bulk readmode. This works just fine, but > > not in all cases. > > > > Also further investigations showed that the linux kernel currently does > > not support reliable reading of Interrupt endpoint data at all, not even > > by using URBs. > > Umm, I beg to differ. I'm using a USB keyboard and mouse right now which > reliably uses Interrupt endpoints, using URB's (the HUD driver). > > That isn't to say you aren't having a problem, but you are definately > overstating it.
Err. I think I did not correctly expressed my problem. The in-kernel drivers work just fine. However I want to use Interrupt Endpoints from USER space, without a special kernel driver. gphoto2 (or better, libusb) currently opens /proc/bus/pci/001/00x and issues USBDEVFS_BULK ioctls to write/read from Bulk and Interrupt endpoints. So I think what I am observing is that interrupt endpoint access from userspace is not very reliable. (I haven't yet booted 2.4.13-ac7 to test the single shot interrupt endpoint URB reader.) Ciao, Marcus _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
