On 25.02.20 09:13, Frieder Schrempf wrote: > 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. So I had a closer look and while the DRM_MXSFB looks ok on its own, I have some problem with the rest of the i.MX8MM display subsystem. The vendor stack, that I'm currently using integrates into the imx-drm master/core driver [1] that binds all the components of the display subsystem, such as the LCDIF driver and the integrated SEC_DSIM DSI bridge. And because of my lack of DRM skills, I have no idea how to get the DRM_MXSFB driver to bind to the imx-drm core, instead of running separately and connecting directly to some panel as it is done for i.MX23/28 and i.MX6SX/UL. [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/gpu/drm/imx/imx-drm-core.c _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
