[PATCH 1/2] dt-bindings: drm/bridge: ti-sn65dsi83: Add enable delay property

[Marek Vasut]

On 12/12/22 13:29, Frieder Schrempf wrote:
> On 12.12.22 10:23, Krzysztof Kozlowski wrote:
>> On 12/12/2022 10:09, Frieder Schrempf wrote:
>>>>>> This does seem like a hardware bug right there, can you double-check
>>>>>> this with the hardware engineer ?
>>>>>
>>>>> Yep, checked with hardware engineer. An 470nF is attached, together
>>>>> with an
>>>>> open drain output and only the internal pull-up. So yes ~113ms rising
>>>>> time
>>>>> until 0.7 x VCC.
>>>>
>>>> I don't suppose you can have that capacitor reduced or better yet, some
>>>> external pull up added, can you ?
>>>
>>> Actually our HW engineers have implemented a similar RC circuit to
>>> provide a hardware delay for the EN signal. I think this is due to a
>>> design note in the datasheet (see chapter 7.4.1) and therefore it's
>>> probably widely spread.
>>
>> If I read section 7.4.1 correctly, it would be enough to just add delay
>> Ten=1ms instead of the capacitor, right? And that would be
>> device-specific. But if one chooses the capacitor solution, it becomes
>> now board specific.
> 
> Yes, seems like that's the case.

Can you still fix the board instead ? It would even save you on BOM.