Messages in this thread | | | Date | Sat, 15 Feb 2003 18:42:54 -0500 | From | "Murray J. Root" <> | Subject | Re: 2.5.61/usb: ioctl control transfer |
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On Sat, Feb 15, 2003 at 11:01:22PM +0100, Andreas Jellinghaus wrote: > I'm using the devfs from a userspace application. > the ioctl USBDEVFS_CONTROL is supposed to return > the number of bytes actualy read from a control > transfer. > > but the return code i get is always what i specified > as length of the buffer. > > since i'm using the same usb control transfers > as the windows drivers and get the same result > back (but return code is always wLength), > i wonder if there is a bug in the kernel. Anyone > has similiar problems? > > Regards, Andreas > (userspace code ...) > syslog(LOG_DEBUG, "usb xmit %02hx %02hx %02hx %02hx 00 00 %02hx %02hx\n" > , > type, req, value >> 8, value&0xff, size >> 8, size & > 0xff); > > if (! (type & 0x80)) debug_hexdump("Sending:", buf, size); > > rc = ioctl(fd, USBDEVFS_CONTROL, &ctrl); > if (rc == -1) { > syslog(LOG_ERR, "usb ioctl control transfer failed:%s\n", > strerror(errno)); > } > syslog(LOG_DEBUG, "ioctl rc %hx size %hx length %hx", > rc, size, ctrl.length); > if (type & 0x80) debug_hexdump("Received:", buf, size); > >
I seem to be seeing the same thing with USB-storage devices - usb-storage sees an error because it got back the same value it sent. It makes mounting usb-storage devices take a LONG time as each send is followed by a device reset since the returned value is unexpected.
-- Murray J. Root
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