[RFC][PATCH 1/2] drm_hwcomposer: Error out on YUV layer as it would fail for single planes

[Alexandru-Cosmin Gheorghe]

On Thu, Mar 08, 2018 at 11:43:25AM -0800, John Stultz wrote:
> On Thu, Mar 8, 2018 at 3:10 AM, Robert Foss <robert.foss at collabora.com> wrote:
> > Hey John,
> >
> >
> > On 03/07/2018 12:19 AM, John Stultz wrote:
> >>
> >> As suggested by Alexandru-Cosmin Gheorghe:
> >>
> >> ConvertHALFormatToDrm logic would work only for 1 plane formats,
> >> and probably gets rejected by drmModeAddFb2, but to save
> >> debugging time  maybe it worth removing DRM_FORMAT_YVU420 from
> >> ConvertHALFormatToDrm and checking it's return code.
> >>
> >> So this patch tries to do this.
> >>
> >> Cc: Marissa Wall <marissaw at google.com>
> >> Cc: Sean Paul <seanpaul at google.com>
> >> Cc: Dmitry Shmidt <dimitrysh at google.com>
> >> Cc: Robert Foss <robert.foss at collabora.com>
> >> Cc: Matt Szczesiak <matt.szczesiak at arm.com>
> >> Cc: Liviu Dudau <Liviu.Dudau at arm.com>
> >> Cc: David Hanna <david.hanna11 at gmail.com>
> >> Cc: Rob Herring <rob.herring at linaro.org>
> >> Cc: Alexandru-Cosmin Gheorghe <Alexandru-Cosmin.Gheorghe at arm.com>
> >> Signed-off-by: John Stultz <john.stultz at linaro.org>
> >> ---
> >>   platformdrmgeneric.cpp | 15 +++++++++++----
> >>   1 file changed, 11 insertions(+), 4 deletions(-)
> >>
> >> diff --git a/platformdrmgeneric.cpp b/platformdrmgeneric.cpp
> >> index 741d42b..33f1ea0 100644
> >> --- a/platformdrmgeneric.cpp
> >> +++ b/platformdrmgeneric.cpp
> >> @@ -76,8 +76,6 @@ uint32_t
> >> DrmGenericImporter::ConvertHalFormatToDrm(uint32_t hal_format) {
> >>         return DRM_FORMAT_ABGR8888;
> >>       case HAL_PIXEL_FORMAT_RGB_565:
> >>         return DRM_FORMAT_BGR565;
> >> -    case HAL_PIXEL_FORMAT_YV12:
> >> -      return DRM_FORMAT_YVU420;
> >
> >
> > I'm not sure I understand the rationale for removing YVU420.
> 
> Mostly its on Alexandru's suggestion, as I don't have any experience
> w/ using YVU420.  Per his suggestion, my sense was that since its a
> multi-plane format it was expected to fail with drmModeAddFB2().
> 
> If that's incorrect, I'm fine with dropping this change.
> 
My line of thought was both DrmGenericImporter::ImportBuffer and 
HisiImporter::ConvertHalFormatToDrm don't work for planar
formats(YVU420), so ConvertHalFormatToDrm should convert only
the formats supported by the Importer. 
I realize now, that I might be wrong since this would also affect
ImportImage, however at first sight DrmGenericImporter::ImportImage 
doesn't seem to support multi-planar as well, isn't it?

> thanks
> -john