Commit 10e48522 authored Jul 10, 2007 by Pete Zaitcev Committed by Greg Kroah-Hartman Jul 19, 2007

USB: usblp: "Big cleanup" breaks O_NONBLOCK



I found the first regresson in the rewritten ("all dynamic" and "no races")
driver. If application uses O_NONBLOCK, I return -EAGAIN despite the URB
being submitted successfuly. This causes the application to resubmit the
same data erroneously.

The fix is to pretend that the transfer has succeeded even if URB was
merely queued. It is the same behaviour as with the old version.

Signed-off-by: Pete Zaitcev <zaitcev@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

parent 9454c46a

drivers/usb/class/usblp.c

+5 −4

Original line number	Diff line number	Diff line
		@@ -741,10 +741,11 @@ static ssize_t usblp_write(struct file file, const char __user buffer, size_t
		*/
		rv = usblp_wwait(usblp, !!(file->f_flags&O_NONBLOCK));
		if (rv < 0) {
		/*
		* If interrupted, we simply leave the URB to dangle,
		* so the ->release will call usb_kill_urb().
		*/
		if (rv == -EAGAIN) {
		/* Presume that it's going to complete well. */
		writecount += transfer_length;
		}
		/* Leave URB dangling, to be cleaned on close. */
		goto collect_error;
		}