lkml.org 
[lkml]   [2007]   [Oct]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: USB: FIx locks and urb->status in adutux
From
Date
On Tue, 2007-10-30 at 06:24, Pete Zaitcev wrote:

> However, this looks wrong:
>
> > + dev->interrupt_in_endpoint->bInterval);
> > + dev->read_urb_finished = 0;
> > + retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
> > + /* we ignore failure */
> > + /* end of fixup for first read */
> > +
> > + /* initialize out direction */
> > + dev->out_urb_finished = 1;
>
> The finished flag is only set when URB is not in use anymore. Did you
> observe an anomaly with my code? Any hangs? If so, I assure you this
> is not the fix. As it's written, even if we ignore the failure (e.g.
> do not pass it to userland), we sill have to maintain the correct
> flag state.

As about read_urb_finished probably it's OK. But we shouldn't decrease open_count in the case of error as then we return normal exit value.
Here is what we had before:

dev->interrupt_in_endpoint->bInterval);
dev->read_urb_finished = 0;
retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
if (retval) {
dev->read_urb_finished = 1;
--dev->open_count;
}

So I can left it but w/o this line:
--dev->open_count;

What is more critical is that I added:

/* initialize out direction */
dev->out_urb_finished = 1;

Without this we'll always have write timeouts.

Vitaliy

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2007-10-30 14:15    [W:0.091 / U:0.392 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site