Hi, Hsin-Yi: On Thu, 2019-05-30 at 17:18 +0800, Hsin-Yi Wang wrote: > mtk_dsi_stop() should be called after mtk_drm_crtc_atomic_disable(), which needs > ovl irq for drm_crtc_wait_one_vblank(), since after mtk_dsi_stop() is called, > ovl irq will be disabled. If drm_crtc_wait_one_vblank() is called after last > irq, it will timeout with this message: "vblank wait timed out on crtc 0". This > happens sometimes when turning off the screen. > > In drm_atomic_helper.c#disable_outputs(), > the calling sequence when turning off the screen is: > > 1. mtk_dsi_encoder_disable() > --> mtk_output_dsi_disable() > --> mtk_dsi_stop(); // sometimes make vblank timeout in atomic_disable > --> mtk_dsi_poweroff(); > 2. mtk_drm_crtc_atomic_disable() > --> drm_crtc_wait_one_vblank(); > ... > --> mtk_dsi_ddp_stop() > --> mtk_dsi_poweroff(); > > mtk_dsi_poweroff() has reference count design, change to make mtk_dsi_stop() > called in mtk_dsi_poweroff() when refcount is 0. Applied to mediatek-drm-fixes-5.2 [1], thanks. [1] https://github.com/ckhu-mediatek/linux.git-tags/commits/mediatek-drm-fixes-5.2 Regards, CK > > Fixes: 0707632b5bac ("drm/mediatek: update DSI sub driver flow for sending commands to panel") > Signed-off-by: Hsin-Yi Wang <hsinyi@xxxxxxxxxxxx> > --- > change log v3->v4: > * add comment in code. > --- > drivers/gpu/drm/mediatek/mtk_dsi.c | 10 +++++++++- > 1 file changed, 9 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c > index b00eb2d2e086..730594a91440 100644 > --- a/drivers/gpu/drm/mediatek/mtk_dsi.c > +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c > @@ -630,6 +630,15 @@ static void mtk_dsi_poweroff(struct mtk_dsi *dsi) > if (--dsi->refcount != 0) > return; > > + /* > + * mtk_dsi_stop() and mtk_dsi_start() is asymmetric, since > + * mtk_dsi_stop() should be called after mtk_drm_crtc_atomic_disable(), > + * which needs irq for vblank, and mtk_dsi_stop() will disable irq. > + * mtk_dsi_start() needs to be called in mtk_output_dsi_enable(), > + * after dsi is fully set. > + */ > + mtk_dsi_stop(dsi); > + > if (!mtk_dsi_switch_to_cmd_mode(dsi, VM_DONE_INT_FLAG, 500)) { > if (dsi->panel) { > if (drm_panel_unprepare(dsi->panel)) { > @@ -696,7 +705,6 @@ static void mtk_output_dsi_disable(struct mtk_dsi *dsi) > } > } > > - mtk_dsi_stop(dsi); > mtk_dsi_poweroff(dsi); > > dsi->enabled = false; _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
