On 26.02.20 17:05, Guido Günther wrote: > On Wed, Feb 26, 2020 at 04:54:35PM +0100, Lucas Stach wrote: >> On Mi, 2020-02-26 at 15:31 +0000, Schrempf Frieder wrote: >>> 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. >> >> It's a separate hardware and it's a pretty major design issue of the >> downstream driver that it integrates into imx-drm. You don't want this >> with the upstream driver. >> >> Maybe Guido (CCed) can give you some clues, as apparently he is using >> the mainline eLCDIF driver + some patches to drive the DSI display path >> on i.MX8MQ. A lot of this will probably be transferable to the i.MX8MM >> display path. > > Newer mxsfb supports attaching a bridge so if you make your DSI host > controller driver a DSI bridge mxsfb can drive it: > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/gpu/drm/mxsfb/mxsfb_drv.c#n268 > > this should be similar to what was done for the imx8mq here (imx8mm > users a different ip core though): > > https://source.puri.sm/guido.gunther/linux-imx8/commits/forward-upstream/next-20200217/mxsfb+nwl/v9-wip > > There's also some additional mxsfb patches by Robert floating around > which aren't mainline yet which the above branch also has. > > Which reminds me that i need to prepare and send out a v9. Thanks Lucas and Guido for pointing out the details! It's very unfortunate that i.MX8MQ and i.MX8MM don't share the same DSI ip core. It seems like I need to try coming up with a bridge driver for the Samsung DSIM DSI controller for a proper upstream solution. Thanks, Frieder _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
