Hi Shuah,
On Thursday 10 Nov 2016 17:16:31 Shuah Khan wrote:
> On 11/10/2016 05:11 PM, Laurent Pinchart wrote:
> > On Thursday 10 Nov 2016 17:00:16 Shuah Khan wrote:
> >> On 11/10/2016 04:53 PM, Laurent Pinchart wrote:
> >>> On Tuesday 08 Nov 2016 12:20:29 Shuah Khan wrote:
> >>>> On Tue, Nov 8, 2016 at 6:55 AM, Sakari Ailus wrote:
> >>>>> From: Sakari Ailus <sakari.ailus@xxxxxx>
> >>>>>
> >>>>> Allow allocating the media device dynamically. As the struct
> >>>>> media_device embeds struct media_devnode, the lifetime of that object
> >>>>> is that same than that of the media_device.
> >>>>>
> >>>>> Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
> >>>>> ---
> >>>>>
> >>>>> drivers/media/media-device.c | 15 +++++++++++++++
> >>>>> include/media/media-device.h | 13 +++++++++++++
> >>>>> 2 files changed, 28 insertions(+)
> >>>>>
> >>>>> diff --git a/drivers/media/media-device.c
> >>>>> b/drivers/media/media-device.c
> >>>>> index a31329d..496195e 100644
> >>>>> --- a/drivers/media/media-device.c
> >>>>> +++ b/drivers/media/media-device.c
> >>>>> @@ -684,6 +684,21 @@ void media_device_init(struct media_device *mdev)
> >>>>> }
> >>>>> EXPORT_SYMBOL_GPL(media_device_init);
> >>>>>
> >>>>> +struct media_device *media_device_alloc(struct device *dev)
> >>>>> +{
> >>>>> + struct media_device *mdev;
> >>>>> +
> >>>>> + mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
> >>>>> + if (!mdev)
> >>>>> + return NULL;
> >>>>> +
> >>>>> + mdev->dev = dev;
> >>>>> + media_device_init(mdev);
> >>>>> +
> >>>>> + return mdev;
> >>>>> +}
> >>>>> +EXPORT_SYMBOL_GPL(media_device_alloc);
> >>>>> +
> >>>>
> >>>> One problem with this allocation is, this media device can't be shared
> >>>> across drivers. For au0828 and snd-usb-audio should be able to share
> >>>> the media_device. That is what the Media Allocator API patch series
> >>>> does.
> >>>
> >>> No disagreement here, Sakari's patches don't address the issues that the
> >>> media allocator API fixes. The media allocator API, when ready, should
> >>> replace (or at least complement, if we decide to keep a simpler API for
> >>> drivers that don't need to share a media device, but I have no opinion
> >>> on this at this time) this allocation function.
> >>
> >> Media Device Allocator API is ready and reviewed. au0828 uses it as the
> >> first driver using it. I will be sending out snd-usb-audio patch soon
> >> that makes use of the shared media device.
> >
> > I don't think it would be too difficult to rebase this series on top of
> > the media allocator API, as all that is needed here is a way to
> > dynamically allocate the media device in a clean fashion. I don't think
> > Sakari's patches depend on a specific implementation of
> > media_device_alloc(). Sakari, please let me know if I got this wrong.
>
> Media Device Allocator API is independent as well. It doesn't make any
> assumptions on media_device register and doesn't care really whether it
> is shared or not. So I think Sakari's work can use the Media Device
> Allocator API instead of the allocator routine it is adding.
I think you're right, and the goal is certainly to merge both. The question is
just which series should go in first. I have no strong opinion on that,
whichever series is ready first can probably get merged first. I'd just like
to get a confirmation from Sakari that both orders would be equally fine.
This being said, I'd of course like to test the combination of both series to
make sure neither introduce an issue for the other one.
> >>>> This a quick review and I will review the patch series and get back to
> >>>> you.
--
Regards,
Laurent Pinchart
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