Re: [PATCH 2/2] drm/panel: simple: Add timings for Raspberry Pi 7" panel

[Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>]

On 13/05/2026 14:52, Tomi Valkeinen wrote:
> Hi,
> 
> On 23/04/2026 18:01, Tomi Valkeinen wrote:
>> Hi,
>>
>> On 23/04/2026 16:54, Marek Vasut wrote:
>>> On 4/23/26 3:16 PM, Tomi Valkeinen wrote:
>>>
>>> Hello Tomi,
>>>
>>>>>> In the past I used this panel compat instead of the
>>>>>> panel-raspberrypi-touchscreen.c and it worked.
>>>>>> IIRC Marek splitted the multi-function module into a regulator and 
>>>>>> the
>>>>>> panel description.
>>>>> Ok... Indeed https://pip.raspberrypi.com/categories/651-pcn lists 
>>>>> PH800480T013 as one of the panels used. Although two variants are 
>>>>> listed, and also a third panel model, possibly from another vendor.
>>>>>
>>>>> My module is v1.1, and I think it has the PH800480T013-IAC21 
>>>>> D/5624/ KIT- LC variant.
>>>> A question to Marek: Where did you get the timings for PH800480T013? 
>>>> Did you find a datasheet?
>>> Search engine first link:
>>>
>>> https://mm.digikey.com/Volume0/opasdata/d220001/medias/docus/5337/ 
>>> PH800480T013-IHC09.pdf
>>
>> I tested the "powertip,ph800480t013-idf02". I'm using BeagleY-AI here, 
>> and it didn't work at all. After some testing, I figured out these:
>>
>> HSW of 2 is much too small. But this could be an issue on the display 
>> controller or the DSI encoder side. HWS of around 8 starts to work ok. 
>> Below that, I don't get anything on the screen.
>>
>> The syncs are interesting. I set them to DISPLAY_FLAGS_VSYNC_HIGH | 
>> DISPLAY_FLAGS_HSYNC_HIGH, Marek to DRM_MODE_FLAG_NVSYNC | 
>> DRM_MODE_FLAG_NHSYNC. But I have sent the TC358762 series, which fixes 
>> the syncs that the bridge sends (20260327-tc358762-fixes- 
>> v2-0-3589d3c45f4a@ideasonboard.com).
>>
>> Flipping the syncs might explain why I used 46 and 23 as the 
>> backporches, Marked used 46-hsw and 23-vsw for backporches (well, 
>> Marek's vbp was off by one as I mentioned).
>>
>> But now I'm getting unsure if my TC358762 fixed the syncs correctly... 
>> I'm pretty sure I measured those with my scope, though.
> I did some digging.
> 
> The upstream TC358762 syncs are wrong, and inverse what they're supposed 
> to be. The upstream powertip,ph800480t013-idf02 timings are such that 
> the image still gets centered correctly, even with the wrong syncs, but 
> this makes the timings not match the datasheet.
> 
> With my TC358762 series, the syncs on the parallel bus are correct, and 
> thus powertip,ph800480t013-idf02 no longer works right. My 
> raspberrypi,7inch-dsi panel timings work right with the TC358762 series, 
> but those panel timings have the sync polarities wrong, and thus the 
> timings are also not according to the datasheet.
> 
> So: we can drop this series. I'll fix the timings for 
> powertip,ph800480t013-idf02, and then it'll work with the RaspberryPi 7" 
> DSI display module...

Ack, thanks for your updates.

-- 
With best wishes
Dmitry