From: Xinlei Lee <xinlei.lee@mediatek.com>

Dsi is turned off at bridge.disable, causing crtc to wait for vblank timeout.
It is necessary to add count protection to turn off dsi, and turn off at post_disable.

Fixes: cde7e2e35c28 ("drm/mediatek: Separate poweron/poweroff from enable/disable and define new funcs")
Signed-off-by: Xinlei Lee <xinlei.lee@mediatek.com>
---
Base on linux-next.
---
---
 drivers/gpu/drm/mediatek/mtk_dsi.c | 15 ++++++---------
 1 file changed, 6 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
index 9cc406e1eee1..157248309c32 100644
--- a/drivers/gpu/drm/mediatek/mtk_dsi.c
+++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
@@ -768,14 +768,6 @@ static void mtk_dsi_bridge_mode_set(struct drm_bridge *bridge,
 	drm_display_mode_to_videomode(adjusted, &dsi->vm);
 }
 
-static void mtk_dsi_bridge_atomic_disable(struct drm_bridge *bridge,
-					  struct drm_bridge_state *old_bridge_state)
-{
-	struct mtk_dsi *dsi = bridge_to_dsi(bridge);
-
-	mtk_output_dsi_disable(dsi);
-}
-
 static void mtk_dsi_bridge_atomic_enable(struct drm_bridge *bridge,
 					 struct drm_bridge_state *old_bridge_state)
 {
@@ -803,12 +795,14 @@ static void mtk_dsi_bridge_atomic_post_disable(struct drm_bridge *bridge,
 {
 	struct mtk_dsi *dsi = bridge_to_dsi(bridge);
 
+	if (dsi->refcount == 1)
+		mtk_output_dsi_disable(dsi);
+
 	mtk_dsi_poweroff(dsi);
 }
 
 static const struct drm_bridge_funcs mtk_dsi_bridge_funcs = {
 	.attach = mtk_dsi_bridge_attach,
-	.atomic_disable = mtk_dsi_bridge_atomic_disable,
 	.atomic_enable = mtk_dsi_bridge_atomic_enable,
 	.atomic_pre_enable = mtk_dsi_bridge_atomic_pre_enable,
 	.atomic_post_disable = mtk_dsi_bridge_atomic_post_disable,
@@ -826,6 +820,9 @@ void mtk_dsi_ddp_stop(struct device *dev)
 {
 	struct mtk_dsi *dsi = dev_get_drvdata(dev);
 
+	if (dsi->refcount == 1)
+		mtk_output_dsi_disable(dsi);
+
 	mtk_dsi_poweroff(dsi);
 }
 
-- 
2.18.0

Il 14/09/22 08:18, xinlei.lee@mediatek.com ha scritto:
> From: Xinlei Lee <xinlei.lee@mediatek.com>
> 
> Dsi is turned off at bridge.disable, causing crtc to wait for vblank timeout.
> It is necessary to add count protection to turn off dsi, and turn off at post_disable.
> 
> Fixes: cde7e2e35c28 ("drm/mediatek: Separate poweron/poweroff from enable/disable and define new funcs")
> Signed-off-by: Xinlei Lee <xinlei.lee@mediatek.com>

Hello Xinlei,
which machine is this commit targeting?

Can you please try to reproduce again the issue that you're seeing with my
mtk_dsi fix [1], but without this commit?

Thanks,
Angelo

[1]: 
https://patchwork.kernel.org/project/linux-mediatek/patch/20220721172727.14624-1-angelogioacchino.delregno@collabora.com/