Re: [PATCH v3 1/1] drm: bridge: ti-sn65dsi83: Fix DSI mode flags for stable LVDS output

[tessolveupstream@gmail.com]

On 24-04-2026 13:55, Luca Ceresoli wrote:
> Hello,
> 
> On Thu Apr 23, 2026 at 11:16 AM CEST, tessolveupstream wrote:
> 
>>> I had reached out to TI for clarification and any related documentation
>>> updates, but I have not received any response so far.Given this, it is
>>> uncertain whether we will be able to obtain further details or official
>>> confirmation from TI in the near term.
>>>
>>> I would appreciate your guidance on how you would prefer us to proceed
>>> from here.
>>
>> I followed up with TI, and they pointed us to the relevant sections in the
>> SN65DSI83/84/86 datasheets covering DSI video transmission specifications.
> 
> Thanks for keeping on! I'm also trying to get info from TI, I'm keeping you
> up to date if that will happen.
> 
>>> https://www.ti.com/lit/ds/symlink/sn65dsi84.pdf?ts=1776924088430&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FSN65DSI84
>>
>> As per datasheet Section 7.4.7, the device operates in DSI video mode with
>> fixed horizontal timing, where HBP, and HFP are explicitly defined and expected
>> to be present as part of the video line structure. The timing description in
>> this section assumes standard non‑burst video transmission with all horizontal
>> blanking intervals accounted for.
>>
>> The datasheet does not document support for DSI video burst mode,
> 
> This sentence seems incorrect. Section 7.4.7 starts with this sentence:
> "The SN65DSI84 supports burst video mode and non-burst video mode ...".
> 
> Even though asa matter of fact it looks like many users have issues that
> get solved by disabling burst mode.
> 
>> nor does it
>> mention support for omitting horizontal front or back porch intervals. In
>> particular, there is no indication that the device can operate with collapsed
>> or suppressed horizontal blanking, as enabled by MIPI_DSI_MODE_VIDEO_BURST,
>> MIPI_DSI_MODE_VIDEO_NO_HFP, or MIPI_DSI_MODE_VIDEO_NO_HBP.
> 
> This is correct.
> 
> We can still try to get TI feedback, but it that won't happen in, say, a
> few weeks then I think we should apply this patch.
>

We have not received any further updates from TI regarding this issue, and 
at this point, we are not sure if we will get additional feedback from them.
As you had mentioned earlier that the patch could be considered after 
waiting for some time, could you please let us know how we can proceed 
further from here?
 
> Luca
> 
> --
> Luca Ceresoli, Bootlin
> Embedded Linux and Kernel engineering
> https://bootlin.com