On 06.08.2018 21:31, Leonard Crestez wrote: > The lcdif block is only powered on when display is active so plane > updates when not enabled are not valid. Writing to an unpowered IP block > is mostly ignored but can trigger bus errors on some chips. > > Prevent this situation by switching to drm_atomic_helper_commit_tail_rpm > and having the drm core ensure atomic_plane_update is only called while > the crtc is active. This avoids having to keep track of "enabled" bits > inside the mxsfb driver. > > This also requires handling the vblank event for disable from > mxsfb_pipe_update. Hm, I don't think this is a new requirement. Simple KMS Helper Reference clearly states that it should be called from update: https://www.kernel.org/doc/html/v4.17/gpu/drm-kms-helpers.html#simple-kms-helper-reference Probably using drm_atomic_helper_commit_tail_rpm just exacerbates an issue which we haven't seen before... Since I think it is a general fix, I'd rather prefer have it in a separate commit. > > Signed-off-by: Leonard Crestez <leonard.crestez@xxxxxxx> > Suggested-by: Stefan Agner <stefan@xxxxxxxx> > --- > drivers/gpu/drm/mxsfb/mxsfb_drv.c | 15 +++++++++++++++ > 1 file changed, 15 insertions(+) > > diff --git a/drivers/gpu/drm/mxsfb/mxsfb_drv.c > b/drivers/gpu/drm/mxsfb/mxsfb_drv.c > index d797dfd40d98..5777e730085b 100644 > --- a/drivers/gpu/drm/mxsfb/mxsfb_drv.c > +++ b/drivers/gpu/drm/mxsfb/mxsfb_drv.c > @@ -96,10 +96,14 @@ static const struct drm_mode_config_funcs > mxsfb_mode_config_funcs = { > .fb_create = drm_gem_fb_create, > .atomic_check = drm_atomic_helper_check, > .atomic_commit = drm_atomic_helper_commit, > }; > > +static const struct drm_mode_config_helper_funcs mxsfb_mode_config_helpers = { > + .atomic_commit_tail = drm_atomic_helper_commit_tail_rpm, > +}; > + > static void mxsfb_pipe_enable(struct drm_simple_display_pipe *pipe, > struct drm_crtc_state *crtc_state, > struct drm_plane_state *plane_state) > { > struct mxsfb_drm_private *mxsfb = drm_pipe_to_mxsfb_drm_private(pipe); > @@ -113,15 +117,25 @@ static void mxsfb_pipe_enable(struct > drm_simple_display_pipe *pipe, > > static void mxsfb_pipe_disable(struct drm_simple_display_pipe *pipe) > { Shouldn't that be in mxsfb_pipe_update? -- Stefan > struct mxsfb_drm_private *mxsfb = drm_pipe_to_mxsfb_drm_private(pipe); > struct drm_device *drm = pipe->plane.dev; > + struct drm_crtc *crtc = &pipe->crtc; > + struct drm_pending_vblank_event *event; > > drm_panel_disable(mxsfb->panel); > mxsfb_crtc_disable(mxsfb); > drm_panel_unprepare(mxsfb->panel); > pm_runtime_put_sync(drm->dev); > + > + spin_lock_irq(&drm->event_lock); > + event = crtc->state->event; > + if (event) { > + crtc->state->event = NULL; > + drm_crtc_send_vblank_event(crtc, event); > + } > + spin_unlock_irq(&drm->event_lock); > } > > static void mxsfb_pipe_update(struct drm_simple_display_pipe *pipe, > struct drm_plane_state *plane_state) > { > @@ -232,10 +246,11 @@ static int mxsfb_load(struct drm_device *drm, > unsigned long flags) > drm->mode_config.min_width = MXSFB_MIN_XRES; > drm->mode_config.min_height = MXSFB_MIN_YRES; > drm->mode_config.max_width = MXSFB_MAX_XRES; > drm->mode_config.max_height = MXSFB_MAX_YRES; > drm->mode_config.funcs = &mxsfb_mode_config_funcs; > + drm->mode_config.helper_private = &mxsfb_mode_config_helpers; > > drm_mode_config_reset(drm); > > pm_runtime_get_sync(drm->dev); > ret = drm_irq_install(drm, platform_get_irq(pdev, 0)); _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
