On 11/10/2016 05:19 PM, Laurent Pinchart wrote:
> 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.
Audio maintainer has been waiting for the snd-usb-audio media controller api
work to use it as a reference for changing other drivers to use media controller
api.
I have an urgency here to get the snd-usb-audio. So I am going to work
towards getting Media Device Allocator API, au0828, and snd-usb-audio patches
that uses Media Device Allocator API into 4.10
Sakari's work could take longer as it requires driver changes. So I am going
to assume, it will happen after the work I am doing.
thanks,
-- Shuah
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