Etnaviv issues on i.MX8M-Mini

[Schrempf Frieder]

Hi Lucas,

On 24.02.20 12:08, Lucas Stach wrote:
> On Mo, 2020-02-24 at 10:53 +0000, Schrempf Frieder wrote:
>> Hi Lucas,
>>
>> On 24.02.20 11:37, Lucas Stach wrote:
>>> Hi Frieder,
>>>
>>> On Mo, 2020-02-24 at 10:28 +0000, Schrempf Frieder wrote:
>>>> On 20.02.20 19:58, Chris Healy wrote:
>>>>> For the jerkey transitions, can you determine if this is a symptom of
>>>>> a low framerate or dropped frames or something else?
>>>>>
>>>>> Perhaps you can start your app with
>>>>> "GALLIUM_HUD=fps,cpu,draw-calls,frametime".  This may give some clues.
>>>>
>>>> The framerate seems ok. I get something between 50 and 70 FPS.
>>>>
>>>> I have a Qt demo app with a menu and an animated 'ball' that moves
>>>> across the screen. When the menu is visible, the ball movement is really
>>>> jerky (ball seems to 'jump back and forth' instead of moving linearly).
>>>>
>>>> As soon as I hide the menu and show the animation fullscreen, the
>>>> movements are perfectly smooth.
>>>>
>>>> Running the same app with software rendering, everything looks good, too.
>>>>
>>>> No idea what that means, though. I probably need to look at the code of
>>>> the app and do some more experiments to get a better idea of what might
>>>> cause the distortion.
>>>>
>>>> Unless some of the graphics experts here already have an idea of what
>>>> can cause and/or how to debug such an issue!?
>>>
>>> Which driver is used for the display side? It seems like the display
>>> side doesn't properly handle the dma fences used to synchronize scanout
>>> and rendering.
>>
>> I ported/picked the drivers for the LCDIF and DSI controllers from
>> development branch of the 5.4-based vendor kernel [1] to our own
>> v5.4-based kernel [2]. So it is quite probable, that something could be
>> wrong here.
> 
> Please just use DRM_MXSFB for the display side, instead of the
> downstream driver.

Hm, good idea. I somehow forgot about the fact, that there is an 
upstream driver for the LCDIF controller. On first try I couldn't get it 
to run on the i.MX8MM, but I suspect that's due to some reset, 
power-domain or clock setup, that is missing upstream. I will see if I 
can get any further with this.

Thanks,
Frieder