Re:Re: Re: Re:[PATCH] drm/panel-edp: Add BOE NV140FHM-N4Z panel entry

["Andy Yan" <andyshrk@163.com>]

Hi Doug,

在 2025-01-16 01:51:15，"Doug Anderson" <dianders@chromium.org> 写道：
>Hi,
>
>On Wed, Jan 15, 2025 at 2:15 AM Andy Yan <andyshrk@163.com> wrote:
>>
>>
>> Hi Doug,
>>
>> 在 2025-01-15 00:44:41，"Doug Anderson" <dianders@chromium.org> 写道：
>> >Hi,
>> >
>> >On Tue, Jan 14, 2025 at 1:05 AM Andy Yan <andyshrk@163.com> wrote:
>> >>
>> >>
>> >> Hi All,
>> >>
>> >> At 2025-01-13 18:17:38, "Andy Yan" <andyshrk@163.com> wrote:
>> >> >
>> >> >Sorry, please don't merge this patch. after further testing,
>> >> >I found that there are still some changce, it can't read edid.
>> >>
>> >> It turns out that we need set hpd-reliable-delay-ms = 120 in dts to ensure
>> >> the right time to access edid.
>> >
>> >That seems awfully high and feels likely to be a problem with your
>> >board design and not the panel. Are you sure HPD is even hooked up
>> >properly on your board? Maybe you're missing a pullup/pulldown config
>> >somewhere? Would it be better to just specify "no-hpd" and get the
>> >full "HPD absent" delay?
>> >
>> >
>> >> So the patch is ok, it is ready for review.
>> >>
>> >> >
>> >> >At 2025-01-13 16:59:54, "Andy Yan" <andyshrk@163.com> wrote:
>> >> >>Add an eDP panel entry for BOE NV140FHM-N4Z.
>> >> >>
>> >> >>No datasheet found for this panel.
>> >
>> >I seem to be able to find a datasheet for something that calls itself
>> >NV140FHM-N4Z, but it might be a different HW version since it has a
>> >different ID. In my datasheet, though, "prepare_to_enable" should be
>> >80 for this panel, not 200. That matches another nearby panel
>> >"NV140WUM-N41". Are you sure you need 200?
>>
>> I am not sure about that value,
>> I searched on the internet, and can't find a datasheet match BOE NV140FHM-NZ
>> I set this value according: NV140FHM-N41, and then do many tests to see if it has
>> any problem.
>>
>> http://www.tfinno.com/PIC/PIC/20215121628440.pdf
>>
>> [    3.021700] panel-simple-dp-aux aux-fded0000.edp: Detected BOE NV140FHM-NZ (0x0b09)
>
>Thanks for the pointer. I will note that the datasheet there shows:
>
>200ms < T3+T4+T5+T6+T8
>
>This is different than I saw in my datasheet, which said:
>
>T4+T5+T6+T8>80ms
>
>Specifically, your time includes T3 and mine doesn't. That's
>important. If you want to add support based on your datasheet then the
>200ms should be in `powered_on_to_enable`, not in `prepare_to_enable`.
>
>Said another way, you have:
>
>delay_200_500_e50_p2e200
>
>If you want timings based on your datasheet of a similar product:
>
>delay_200_500_e50_po2e200
>
>If you want timings based on my datasheet of a similar product:
>
>delay_200_500_e50_p2e80
>
>I'll let you pick whichever you feel more comfortable with.


Very appreciate your thoughtful guidance. I will send V2 after more tests.


>
>-Doug