On Thu, May 28, 2020 at 10:19:46AM +0200, Stefan Agner wrote: > On 2020-05-28 10:06, Daniel Vetter wrote: > > On Thu, May 28, 2020 at 9:56 AM Stefan Agner <ste...@agner.ch> wrote: > >> > >> Hi Daniel, > >> > >> On 2020-05-28 07:46, Daniel Vetter wrote: > >> > On Wed, May 27, 2020 at 11:47:56AM +0200, Daniel Vetter wrote: > >> >> mxsfb has vblank support, is atomic, but doesn't call > >> >> drm_crtc_vblank_on/off as it should. Not good. > >> >> > >> >> With my next patch to add the drm_crtc_vblank_reset to helpers this > >> >> means not even the very first crtc enabling will vblanks work anymore, > >> >> since they'll just stay off forever. > >> >> > >> >> Since mxsfb doesn't have any vblank waits of its own in the > >> >> enable/disable flow, nor an enable/disable_vblank callback we can do > >> >> the on/off as the first respectively last operation, and it should all > >> >> work. > >> >> > >> >> Signed-off-by: Daniel Vetter <daniel.vet...@intel.com> > >> >> Cc: Marek Vasut <ma...@denx.de> > >> >> Cc: Stefan Agner <ste...@agner.ch> > >> >> Cc: Shawn Guo <shawn...@kernel.org> > >> >> Cc: Sascha Hauer <s.ha...@pengutronix.de> > >> >> Cc: Pengutronix Kernel Team <ker...@pengutronix.de> > >> >> Cc: Fabio Estevam <feste...@gmail.com> > >> >> Cc: NXP Linux Team <linux-...@nxp.com> > >> >> Cc: linux-arm-ker...@lists.infradead.org > >> > > >> > Ping for some ack/review on this one here, it's holding up the subsystem > >> > wide fix in patch 2. > >> > >> Sorry for the delay. > >> > >> I guess that has the same effect as patch 14 in Laurent's patchset would > >> have: > >> https://lore.kernel.org/dri-devel/20200309195216.31042-15-laurent.pinch...@ideasonboard.com/ > > > > Uh, looking at that patch I realized that mxsfb indeed calls > > drm_vblank_init before mode_config.num_crtc is set. Which means it > > never had working vblank support in upstream. That also explains the > > lack of fireworks, since all other drivers that actually do initialize > > vblank support have the drm_crtc_vblank_on/off calls - without them > > the driver doesn't survive for very long. > > > > tldr; I don't need this patch here to apply the 2nd one, so no > > conflict potential at all. And the patch from Laurent does fix up > > everything correctly, so we should be good. > > Uh I see, that is somehow unfortunate and fortunate at the same time! > > Ok, I hope we get this cleaned up soon.
I recommend igt tests for actually making sure your driver does something, instead of just thinking you've enabled a feature :-) -Daniel > > -- > Stefan > > > -Daniel > > > >> But should be rather trivial to rebase. So until Laurent's patchset is > >> ready, we can go with this fix. > >> > >> Acked-by: Stefan Agner <ste...@agner.ch> > >> > >> -- > >> Stefan > >> > >> > > >> > Thanks, Daniel > >> > > >> >> --- > >> >> drivers/gpu/drm/mxsfb/mxsfb_drv.c | 2 ++ > >> >> 1 file changed, 2 insertions(+) > >> >> > >> >> diff --git a/drivers/gpu/drm/mxsfb/mxsfb_drv.c > >> >> b/drivers/gpu/drm/mxsfb/mxsfb_drv.c > >> >> index 497cf443a9af..1891cd6deb2f 100644 > >> >> --- a/drivers/gpu/drm/mxsfb/mxsfb_drv.c > >> >> +++ b/drivers/gpu/drm/mxsfb/mxsfb_drv.c > >> >> @@ -124,6 +124,7 @@ static void mxsfb_pipe_enable(struct > >> >> drm_simple_display_pipe *pipe, > >> >> drm_panel_prepare(mxsfb->panel); > >> >> mxsfb_crtc_enable(mxsfb); > >> >> drm_panel_enable(mxsfb->panel); > >> >> + drm_crtc_vblank_on(&pipe->crtc); > >> >> } > >> >> > >> >> static void mxsfb_pipe_disable(struct drm_simple_display_pipe *pipe) > >> >> @@ -133,6 +134,7 @@ static void mxsfb_pipe_disable(struct > >> >> drm_simple_display_pipe *pipe) > >> >> struct drm_crtc *crtc = &pipe->crtc; > >> >> struct drm_pending_vblank_event *event; > >> >> > >> >> + drm_crtc_vblank_off(&pipe->crtc); > >> >> drm_panel_disable(mxsfb->panel); > >> >> mxsfb_crtc_disable(mxsfb); > >> >> drm_panel_unprepare(mxsfb->panel); > >> >> -- > >> >> 2.26.2 > >> >> -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel
