[ Upstream commit 2458d9d6d94be982b917e93c61a89b4426f32e31 ]
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.
Fixes: 0707632b5bac ("drm/mediatek: update DSI sub driver flow for sending commands to panel") Signed-off-by: Hsin-Yi Wang hsinyi@chromium.org Signed-off-by: CK Hu ck.hu@mediatek.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 413313f19c36..c1b8caad65e6 100644 --- a/drivers/gpu/drm/mediatek/mtk_dsi.c +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c @@ -631,6 +631,15 @@ 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)) { @@ -697,7 +706,6 @@ static void mtk_output_dsi_disable(struct mtk_dsi *dsi) } }
- mtk_dsi_stop(dsi); mtk_dsi_poweroff(dsi);
dsi->enabled = false;