[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 at quicinc.com> wrote:
>>>>
>>>>
>>>>
>>>> On 11/29/2024 9:52 PM, Dmitry Baryshkov wrote:
>>>>> On Fri, 29 Nov 2024 at 09:59, Xiangxu Yin <quic_xiangxuy at quicinc.com> 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 at quicinc.com>
>>>>>> ---
>>>>>>   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(+)
>>>
>>>
>>
>