Etnaviv issues on i.MX8M-Mini

[Lucas Stach]

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.

Regards,
Lucas