Re: [PATCH] Fix suspend/resume of pxa_camera driver

Robert Jarzmik
2008-07-28T18:33:29Z

Guennadi Liakhovetski <g.liakhovetski@gmx.de> writes:

> On Sun, 27 Jul 2008, Robert Jarzmik wrote:
>
> Yes, this is the difference. The sensor is attached to the camera host
> only on open. In fact, I am not sure, how video applications should behave
> during a suspend / resume cycle. If you suspend, while, say, recording
> from your camera, should you directly continue recording after a wake up?
> How do currect drivers implement this? Or, in general, for example with
> audio - if you suspend while listening to a stream over the net, or to a
> CD, or to a mp3-file on your local disk, should the sound resume after a
> wake up? I added linux-pm for some authoritative answers:-)
AFAIK, on resume, sound streams continues. So the normal behaviour would be to
continue video stream too (as done in ALSA). This supposes the whole video chip
state is saved on suspend and restored on resume, of course.

> If you know how a v4l2 device should handle suspend/resume, or when we get
> some answers, let's try to do it completely-
Of course. In a week or two, my mt9m111 driver will be ready for submission, and
in the review process I'll post a submission for complete suspend/resume.

>> For the camera part, by now, I'm using standard suspend/resume functions of the
>> platform driver (mt9m111.c). It does work, but it's not clean ATM. The chaining
>> between the driver resume function and the availability of the I2C bus are not
>> properly chained. I'm still working on it.
>
> Yes, we have to clarify this too.
Yes.

So, to sum up :
- I finish the mt9m111 driver
- I submit it
- I cook up a clean suspend/resume (unless you did it first of course :)

--
Robert