Re: [PATCH v2] staging: comedi: comedi_test: fix timer lock-up

[Ian Abbott]

On 30/10/14 20:29, Greg Kroah-Hartman wrote:
> On Thu, Oct 30, 2014 at 10:03:53AM +0000, Ian Abbott wrote:
> > Commit 240512474424 ("staging: comedi: comedi_test: use
> > comedi_handle_events()") resulted in the timer routine
> > `waveform_ai_interrupt()` calling `comedi_handle_events()` instead of
> > `comedi_events()`.  That had the advantage of automatically stopping the
> > acquisition on overflow/error/end-of-acquisition conditions (by calling
> > the comedi subdevice's "cancel" handler), but currently results in the
> > timer routine locking when one of those conditions occur.  This is
> > because the "cancel" handler `waveform_ai_cancel()` calls
> > `del_timer_sync()`.
> >
> > Fix it by adding a bit to the device private data that indicates whether
> > the acquisition is active or not, and changing the "cancel" handler to
> > use `del_timer()` instead of `del_timer_sync()`.  The bit is set when
> > starting the acquisition, cleared when ending the acquisition (in the
> > "cancel" handler), and tested in the timer routine, which will do
> > nothing if the acquisition is inactive.  Also, make sure any scheduled
> > timeout event gets cancelled when the low-level device gets "detached"
> > from the comedi core by calling `del_timer_sync()` in the "detach"
> > handler `waveform_detach()`.
> >
> > Fixes: 240512474424 ("staging: comedi: comedi_test: use comedi_handle_events()")
> > Signed-off-by: Ian Abbott <abbotti@xxxxxxxxx>
> > ---
> > v2: rebased after commit dd28153b2a8ca
> > Greg, this fix is for "linux-next" and "staging-next".
>
> I don't understand, I've already taken this patch, right?  It doesn't
> apply to my branch :(

So you have.  Ignore v2 then.  (I got a merge merge conflict when I 
tried it, which is why I sent the rebased version.)

Thanks.

--
-=( Ian Abbott @ MEV Ltd.    E-mail: <abbotti@xxxxxxxxx> )=-
-=(                          Web: http://www.mev.co.uk/  )=-
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/