Hi, On Tue, Mar 03, 2020 at 11:43:14AM +0000, Schrempf Frieder wrote: > On 02.03.20 09:44, Frieder Schrempf wrote: > > 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. > > Sorry to bother you with one more question from a DRM newbie. > > I'm currently looking at Guido's code for the NWL DSI bridge and trying > to convert the NXP SEC DSIM host driver to a bridge driver. > > The NWL driver uses mipi_dsi_host_register(), which searches for a > output (panel) child node under the DSI bridge's node [1] as described > in the bindings example [2]. > > How is this supposed to work in a setup with another bridge after the > DSI bridge, where that bridge is not a child node of the DSI bridge, but > only connected via the DSI bridges output port? For example I have a > DSI->LVDS bridge, that is attached to an I2C port. You can also attach another bridge instead of a panel. NXPs BSP uses a driver very similar to the nwl one above and this is how they attach a DSI->HDMI bridge: https://source.codeaurora.org/external/imx/linux-imx/tree/arch/arm64/boot/dts/freescale/imx8mq-evk-lcdif-adv7535.dts?h=imx_5.4.0_8dxlphantom_er#n56 Cheers, -- Guido > > [1] > https://elixir.bootlin.com/linux/latest/source/drivers/gpu/drm/drm_mipi_dsi.c#L284 > > [2] > https://source.puri.sm/guido.gunther/linux-imx8/blob/forward-upstream/next-20200226/mxsfb+nwl/v9-wip/Documentation/devicetree/bindings/display/bridge/nwl-dsi.yaml#L173 > > Thanks, > Frieder _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
