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SubjectRe: 'scheduling while atomic' during ppp connection on 2.6.37.1 and 2.6.38
On 21/03/2011 11:27, Alan Cox wrote:
> It's quite likely that was as broken before your change as after. The
> locking in the code makes no sense so I flagged it up. The
> nozomi ntty_write also has lots of oddness in it that really needs
> sorting out.
>
> I suspect that the chunk
>
> if (!dc || !port)
> return -ENODEV;
>
> mutex_lock(&port->tty_sem);
>
> if (unlikely(!port->port.count)) {
> DBG1(" ");
> goto exit;
> }
>
> and
>
> /* notify card */
> if (unlikely(dc == NULL)) {
> DBG1("No device context?");
> goto exit;
> }
>
> and the mutex unlock are actually not doing anything
>
> On the write_room case I think that as the code already uses tty_port
> helpers it needs to simply just return the correct value and not do all
> the other checks. chars_in_buffer() likewise
>
> So in fact I don't think at this point the tty_sem needs replacing with
> anything, but the various bogus port.count checks want ripping out.
>
>

Thank you very much for the explanation. I will do my best to respin the
patch with appropriate changes.

Jack


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