Messages in this thread | | | Date | Thu, 24 Sep 2009 23:15:00 +0200 | From | Johan Hovold <> | Subject | Re: [PATCH] USB: ftdi_sio: Remove tty->low_latency. |
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On Thu, Sep 24, 2009 at 08:21:07PM +0100, Alan Cox wrote: > On Thu, 24 Sep 2009 21:03:47 +0200 > Oliver Neukum <oliver@neukum.org> wrote:
> > Am Donnerstag, 24. September 2009 17:40:23 schrieb Johan Hovold: > > > Is there a reason why this was not fixed in ftdi_sio (and whiteheat?) > > > along with the other drivers?
> > No good reason. They escaped my grep pattern. Mea culpa.
> ftdi_sio is correct with low_latency set as it uses a work queue to > process the packets received.
AFAICT it only uses the work queue if tty_buffer_request_room fails to allocate enough space. This being the exception, the completion handler normally processes the packets in interrupt context and this is where I get my lockdep traces (and it happens every time I hit the echo or throttle paths).
/Johan
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