Hi Shuah,

On Thu, Dec 08, 2016 at 07:46:03AM -0700, Shuah Khan wrote:

Hi Sakari,

On 12/07/2016 03:27 PM, Sakari Ailus wrote:

quoted

Hi Shuah,

On Wed, Dec 07, 2016 at 01:03:59PM -0700, Shuah Khan wrote:

quoted

Hi Sakari,

On 12/07/2016 03:52 AM, Sakari Ailus wrote:

quoted

Hi Shuah,

On Mon, Dec 05, 2016 at 05:38:23PM -0700, Shuah Khan wrote:

quoted

On 12/05/2016 04:21 PM, Laurent Pinchart wrote:

quoted

Hi Shuah,

On Monday 05 Dec 2016 15:44:30 Shuah Khan wrote:

quoted

On 11/30/2016 03:01 PM, Shuah Khan wrote:

quoted

Change ALSA driver to use Media Controller API to share media resources
with DVB, and V4L2 drivers on a AU0828 media device.

Media Controller specific initialization is done after sound card is
registered. ALSA creates Media interface and entity function graph
nodes for Control, Mixer, PCM Playback, and PCM Capture devices.

snd_usb_hw_params() will call Media Controller enable source handler
interface to request the media resource. If resource request is granted,
it will release it from snd_usb_hw_free(). If resource is busy, -EBUSY is
returned.

Media specific cleanup is done in usb_audio_disconnect().

Signed-off-by: Shuah Khan <redacted>

Hi Takashi,

If you are good with this patch, could you please Ack it, so Mauro
can pull it into media tree with the other two patches in this series,
when he is ready to do so.

I *really* want to address the concerns raised by Sakari before pulling more 
code that makes fixing the race conditions more difficult. Please, let's all 
work on fixing the core code to build a stable base on which we can build 
additional features. V4L2 and MC need teamwork, it's time to give the 
subsystem the love it deserves.

Hi Laurent,

The issue Sakari brought up is specific to using devm for video_device in
omap3 and vsp1. I tried reproducing the problem on two different drivers
and couldn't on Linux 4.9-rc7.

After sharing that with Sakari, I suggested to Sakari to pull up his patch
that removes the devm usage and see if he still needs all the patches in his
patch series. He didn't back to me on that. I also requested him to rebase on

Just to see what remains, I made a small hack to test this with omap3isp by
just replacing the devm_() functions by their plain counterparts. The memory
is thus never released, for there is no really a proper moment to release it

--- something which the patchset resolves. The result is here:

<URL:http://www.retiisi.org.uk/v4l2/tmp/media-ref-dmesg.txt>

Did you test this on 4.9-rc7 without any of your other patches? If you
haven't could you please run this test with just the removing devm usage
from omap3isp?

It would be good to get a baseline on the current with just the not using
devm first and then see what needs fixing.

Also, could you please send me the complete dmesg.

Updated from v4.9-rc6 to rc7 and with increased CONFIG_LOG_BUF_SHIFT. The
diff and dmesg are here:

<URL:http://www.retiisi.org.uk/v4l2/tmp/media-ref-diff2.txt>
<URL:http://www.retiisi.org.uk/v4l2/tmp/media-ref-dmesg2.txt>

Does unbind work on this even without streaming? Could you suppress

It's been working as long as I remember. There are caveats though --- the
clock to the sensor is provided by the ISP, so obviously things will not
work until the sensor is rebound as well. That is unrelated to the media
framework though; just FYI.

debug messages and run unbind without streaming. It might fail. Let
me know if what you see with just unbind on this driver.

I don't think disabling debug messages makes a difference but sure I can
provide you a log on that. But that'll be tomorrow.

I unearthed an old Gumstix Overo that was hiding in my hardware stash
and I am setting it up to test.

Is it supported in mainline? I have a Nokia N9...

-- 
Kind regards,

Sakari Ailus
e-mail: sakari.ailus@iki.fi	XMPP: sailus@retiisi.org.uk