Re: [PATCH 7/7] media: qcom: iris: describe QC10C as TP10

[Nicolas Dufresne <nicolas.dufresne@collabora.com>]

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Le mercredi 04 novembre 2026 à 14:11 -0800, Rob Clark a écrit :
> On Wed, Nov 4, 2026 at 11:00 AM Robert Mader <robert.mader@collabora.com> wrote:
> > 
> > Nice, very happy to see the series!
> > 
> > On 04.11.26 17:36, Dmitry Baryshkov wrote:
> > > The comment describing the QC10C buffer layout calls it a compressed
> > > P010. It is not:
> > 
> > If I'm not mistaken the display engine / the DRM side (including Mesa)
> > describes it as P010+QCOM_COMPRESSED as well, and so does my pending
> > Gstreamer MR [1] . So if we can't pretend that QC10C ==
> > P010+QCOM_COMPRESSED, then we probably need a DRM_FORMAT_TP10, wire that
> > up everywhere etc. OTOH if we want to keep the DRM side as is, then the
> > comment should reflect that, IMO.
> 
> IMHO we need DRM_FORMAT_TP10.. on the GPU side, we have TP10 and P010
> as distinct formats, both with and without UBWC.  I'm not sure if the
> same is true on video side but P010+UBWC was never exposed, or if it
> truely only supports linear P010 and UBWC TP10.

Xilinx ZynMP is all matching TP10 (they had GEY and YUV semi-planar variants),
but they never upstreamed it, hence why we don't have it in V4L2. Just fyi, we
named it creatively NV12_10LE32 in GStreamer, but careful, I cannot guaranty the
padding in on the same side.

Though, how do we deal with backward compat here?

> 
> BR,
> -R
> 
> > Best regards,
> > 
> > Robert
> > 
> > 1: https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/8195
> > 
> > > P010 stores each sample in 16 bits, QC10C packs three
> > > 10-bit samples in each 32-bit word, which is what the stride computed
> > > below (width * 4 / 3) assumes. Name the format correctly.
> > > 
> > > Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
> > > ---
> > >   drivers/media/platform/qcom/iris/iris_buffer.c | 2 +-
> > >   1 file changed, 1 insertion(+), 1 deletion(-)
> > > 
> > > diff --git a/drivers/media/platform/qcom/iris/iris_buffer.c b/drivers/media/platform/qcom/iris/iris_buffer.c
> > > index eb8de60c1177..ec2bf2a2d953 100644
> > > --- a/drivers/media/platform/qcom/iris/iris_buffer.c
> > > +++ b/drivers/media/platform/qcom/iris/iris_buffer.c
> > > @@ -266,7 +266,7 @@ static u32 iris_yuv_buffer_size_qc08c(struct iris_inst *inst)
> > > 
> > >   /*
> > >    * QC10C:
> > > - * UBWC-compressed format for P010.
> > > + * UBWC-compressed TP10, YUV 4:2:0 with three 10 bit samples packed in 32 bits.
> > >    * Contains 4 planes in the following order -
> > >    * (A) Y_Meta_Plane
> > >    * (B) Y_UBWC_Plane
> > > 

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