[PATCH v2] media: mtk-vcodec: fix builds when remoteproc is disabled

[Alexandre Courbot]

On Fri, Oct 9, 2020 at 1:13 AM Hans Verkuil <hverkuil-cisco at xs4all.nl> wrote:
>
> On 08/10/2020 16:02, Alexandre Courbot wrote:
> > Hi Hans, thanks for taking the time to look at this!
> >
> > On Thu, Oct 8, 2020 at 10:12 PM Hans Verkuil <hverkuil-cisco at xs4all.nl> wrote:
> >>
> >> On 08/10/2020 15:07, Hans Verkuil wrote:
> >>> Hi Alexandre,
> >>>
> >>> On 04/10/2020 14:22, Alexandre Courbot wrote:
> >>>> The addition of MT8183 support added a dependency on the SCP remoteproc
> >>>> module. However the initial patch used the "select" Kconfig directive,
> >>>> which may result in the SCP module to not be compiled if remoteproc was
> >>>> disabled. In such a case, mtk-vcodec would try to link against
> >>>> non-existent SCP symbols. "select" was clearly misused here as explained
> >>>> in kconfig-language.txt.
> >>>>
> >>>> Replace this by a "depends" directive on at least one of the VPU and
> >>>> SCP modules, to allow the driver to be compiled as long as one of these
> >>>> is enabled, and adapt the code to support this new scenario.
> >>>>
> >>>> Also adapt the Kconfig text to explain the extra requirements for MT8173
> >>>> and MT8183.
> >>>>
> >>>> Reported-by: Sakari Ailus <sakari.ailus at linux.intel.com>
> >>>> Signed-off-by: Alexandre Courbot <acourbot at chromium.org>
> >>>> Acked-by: Randy Dunlap <rdunlap at infradead.org> # build-tested
> >>>> ---
> >>>>  drivers/media/platform/Kconfig                | 10 +--
> >>>>  .../media/platform/mtk-vcodec/mtk_vcodec_fw.c | 72 ++++++++++++-------
> >>>>  2 files changed, 54 insertions(+), 28 deletions(-)
> >>>>
> >>>> diff --git a/drivers/media/platform/Kconfig b/drivers/media/platform/Kconfig
> >>>> index a3cb104956d5..98eb62e49ec2 100644
> >>>> --- a/drivers/media/platform/Kconfig
> >>>> +++ b/drivers/media/platform/Kconfig
> >>>> @@ -253,14 +253,16 @@ config VIDEO_MEDIATEK_VCODEC
> >>>>      depends on MTK_IOMMU || COMPILE_TEST
> >>>>      depends on VIDEO_DEV && VIDEO_V4L2
> >>>>      depends on ARCH_MEDIATEK || COMPILE_TEST
> >>>> +    depends on VIDEO_MEDIATEK_VPU || MTK_SCP
> >>>
> >>> Close, but no cigar.
> >>>
> >>> If VIDEO_MEDIATEK_VPU=y and MTK_SCP=m, then VIDEO_MEDIATEK_VCODEC can be configured
> >>> to y, and then it won't be able to find the scp_ functions.
> >>>
> >>> To be honest, I'm not sure how to solve this.
> >>
> >> Found it. Add this:
> >>
> >>         depends on MTK_SCP || !MTK_SCP
> >>         depends on VIDEO_MEDIATEK_VPU || !VIDEO_MEDIATEK_VPU
> >>
> >> Ugly as hell, but it appears to be the correct incantation for this.
> >
> > But doesn't it mean that the driver can be compiled if !MTK_SCP and
> > !VIDEO_MEDIATEK_VPU? That's the one case we want to avoid.
>
> No, because you still have:
>
>         depends on VIDEO_MEDIATEK_VPU || MTK_SCP
>
> So at least one of these must be set.
>
> Just try it :-)

Aha, I misread your message and thought you suggested replacing the
dependencies with these two lines. In this case it would certainly
work! Thanks for the suggestion, I'll send a v3 soon.

>
> Regards,
>
>         Hans