Re: [PATCH 0/7] staging: vc04_services: Some dead code removal

[Stefan Wahren]

Hi,

Am 17.10.2018 um 11:55 schrieb Dave Stevenson:
> On Mon, 15 Oct 2018 at 17:27, Eric Anholt <eric@xxxxxxxxxx> wrote:
>> Stefan Wahren <stefan.wahren@xxxxxxxx> writes:
>>
>>> Hi Tuomas,
>>>
>>>> Tuomas Tynkkynen <tuomas.tynkkynen@xxxxxx> hat am 4. Oktober 2018 um 11:37 geschrieben:
>>>>
>>>>
>>>> Drop various pieces of dead code from here and there to get rid of
>>>> the remaining users of VCHI_CONNECTION_T. After that we get to drop
>>>> entire header files worth of unused code.
>>>>
>>>> I've tested on a Raspberry Pi Model B (bcm2835_defconfig) that
>>>> snd-bcm2835 can still play analog audio just fine.
>>>>
>>> thanks and i'm fine with your patch series:
>>>
>>> Acked-by: Stefan Wahren <stefan.wahren@xxxxxxxx>
>>>
>>> Unfortunately this would break compilation of the downstream vchi
>>> drivers like vcsm [1]. Personally i don't want to maintain another
>>> one, because i cannot see the gain of the resulting effort.
>>>
>>> [1] - https://github.com/raspberrypi/linux/tree/rpi-4.14.y/drivers/char/broadcom/vc_sm
> I'm happy enough to work around these changes. Once the change is in a
> released kernel we can merge a modified version of vc_sm into the
> downstream kernel branch. It's not as if it requires big changes.
>
>> I think the main concern would be if we removed things necessary for
>> 6by9's new vcsm (the one that will let us do dma-buf sharing between
>> media decode and DRM).
> The new vcsm uses the same VCHI service as the existing downstream vc_sm driver.
> The video codec driver don't use any VCHI functionality over and above
> the camera. It goes via a slightly extended version of the
> mmal-vchiq.c, which I have split out into a shared module.

my statement about the old vc_sm based on assumption there wont be a
user of this driver.

In case the camera driver would use the new vc_sm driver, i would be
happier to see this merged in staging than in downstream.

Stefan

>
>> On the other hand, git revert is a thing, so it's not like we actually
>> lose anything.
> :-)
>
>   Dave