Re: [PATCH 6/8] drm/msm/dp: Add maximum width limitation for modes

[Abhinav Kumar]

On 12/3/2024 5:58 AM, Dmitry Baryshkov wrote:
> On Tue, Dec 03, 2024 at 03:41:53PM +0800, Xiangxu Yin wrote:
> > On 12/2/2024 5:32 PM, Dmitry Baryshkov wrote:
> > > On Mon, 2 Dec 2024 at 11:05, Xiangxu Yin <quic_xiangxuy@xxxxxxxxxxx> wrote:
> > > > On 11/29/2024 9:52 PM, Dmitry Baryshkov wrote:
> > > > > On Fri, 29 Nov 2024 at 09:59, Xiangxu Yin <quic_xiangxuy@xxxxxxxxxxx> wrote:
> > > > > > Introduce a maximum width constraint for modes during validation. This
> > > > > > ensures that the modes are filtered based on hardware capabilities,
> > > > > > specifically addressing the line buffer limitations of individual pipes.
> > > > >
> > > > > This doesn't describe, why this is necessary. What does "buffer
> > > > > limitations of individual pipes" mean?
> > > > > If the platforms have hw capabilities like being unable to support 8k
> > > > > or 10k, it should go to platform data
> > > > It's SSPP line buffer limitation for this platform and only support to 2160 mode width.
> > > > Then, shall I add max_width config to struct msm_dp_desc in next patch? for other platform will set defualt value to ‘DP_MAX_WIDTH 7680'
> > >
> > > SSPP line buffer limitations are to be handled in the DPU driver. The
> > > DP driver shouldn't care about those.
> > Ok, Will drop this part in next patch.
>
> If you drop it, what will be left from the patch itself?

Yes agree with Dmitry, max_width is really not a DP related terminology.

This patch should be dropped.

So there were two issues, overall in this series causing this patch:

1) In https://patchwork.freedesktop.org/patch/625822/, instead of using 
VIG_SDM845_MASK, we should be using VIG_SDM845_MASK_SDMA. Without that 
even 2k will not work, will leave a comment there.

2) 4k will still fail. I dont think we can even support 4k on QCS615 but 
the modes should be filtered out because there is no 3dmux.

I have submitted https://patchwork.freedesktop.org/patch/627694/ to 
address this.

Xiangxu, please let me know if that works for you.

Thanks

Abhinav
> > > > > > Signed-off-by: Xiangxu Yin <quic_xiangxuy@xxxxxxxxxxx>
> > > > > > ---
> > > > > >   drivers/gpu/drm/msm/dp/dp_display.c |  3 +++
> > > > > >   drivers/gpu/drm/msm/dp/dp_display.h |  1 +
> > > > > >   drivers/gpu/drm/msm/dp/dp_panel.c   | 13 +++++++++++++
> > > > > >   drivers/gpu/drm/msm/dp/dp_panel.h   |  1 +
> > > > > >   4 files changed, 18 insertions(+)