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drm/msm/dp: check hpd_state before push idle pattern at dp_bridge_disable()

Message ID 1660077890-31622-1-git-send-email-quic_khsieh@quicinc.com (mailing list archive)
State Superseded
Headers show
Series drm/msm/dp: check hpd_state before push idle pattern at dp_bridge_disable() | expand

Commit Message

Kuogee Hsieh Aug. 9, 2022, 8:44 p.m. UTC
dp_bridge_disable() is the first step toward tearing down main link.
Its major function is to start transmitting idle pattern to replace
video stream. This patch will check hpd_state to make sure main link
is enabled before commit changes of main link's configuration to
push idle pattern out to avoid system crashing due to main link clock
is disabled while access main link registers.

Fixes: 13ea4799a81b ("drm/msm/dp: remove extra wrappers and public functions");
Signed-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com>

Reported-by: Leonard Lausen @leezu
---
 drivers/gpu/drm/msm/dp/dp_display.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

Comments

Abhinav Kumar Aug. 9, 2022, 9:55 p.m. UTC | #1
On 8/9/2022 1:44 PM, Kuogee Hsieh wrote:
> dp_bridge_disable() is the first step toward tearing down main link.
> Its major function is to start transmitting idle pattern to replace
> video stream. This patch will check hpd_state to make sure main link
> is enabled before commit changes of main link's configuration to
> push idle pattern out to avoid system crashing due to main link clock
> is disabled while access main link registers.
> 
> Fixes: 13ea4799a81b ("drm/msm/dp: remove extra wrappers and public functions");
there should be no ; at the end
> Signed-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com>
> 
> Reported-by: Leonard Lausen @leezu

We should check the email address of the reporter , this is not right.

> ---
>   drivers/gpu/drm/msm/dp/dp_display.c | 10 ++++++++++
>   1 file changed, 10 insertions(+)
> 
> diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
> index b36f8b6..678289a 100644
> --- a/drivers/gpu/drm/msm/dp/dp_display.c
> +++ b/drivers/gpu/drm/msm/dp/dp_display.c
> @@ -1729,10 +1729,20 @@ void dp_bridge_disable(struct drm_bridge *drm_bridge)
>   	struct msm_dp_bridge *dp_bridge = to_dp_bridge(drm_bridge);
>   	struct msm_dp *dp = dp_bridge->dp_display;
>   	struct dp_display_private *dp_display;
> +	u32 state;
>   
>   	dp_display = container_of(dp, struct dp_display_private, dp_display);
>   
> +	mutex_lock(&dp_display->event_mutex);
> +
> +	state = dp_display->hpd_state;
> +	if (state != ST_DISCONNECT_PENDING && state != ST_CONNECTED) {
> +		mutex_unlock(&dp_display->event_mutex);
> +		return;
> +	}
> +
>   	dp_ctrl_push_idle(dp_display->ctrl);
> +	mutex_unlock(&dp_display->event_mutex);
>   }
>   
>   void dp_bridge_post_disable(struct drm_bridge *drm_bridge)
Stephen Boyd Aug. 10, 2022, 2:10 a.m. UTC | #2
Quoting Kuogee Hsieh (2022-08-09 13:44:50)
> dp_bridge_disable() is the first step toward tearing down main link.
> Its major function is to start transmitting idle pattern to replace
> video stream. This patch will check hpd_state to make sure main link
> is enabled before commit changes of main link's configuration to
> push idle pattern out to avoid system crashing due to main link clock
> is disabled while access main link registers.
>
> Fixes: 13ea4799a81b ("drm/msm/dp: remove extra wrappers and public functions");

Does it really fix 375a126090b9 ("drm/msm/dp: tear down main link at
unplug handle immediately")? I don't see how removing extra wrappers
caused us to start trying to set the idle pattern when the device was
unclocked.
diff mbox series

Patch

diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
index b36f8b6..678289a 100644
--- a/drivers/gpu/drm/msm/dp/dp_display.c
+++ b/drivers/gpu/drm/msm/dp/dp_display.c
@@ -1729,10 +1729,20 @@  void dp_bridge_disable(struct drm_bridge *drm_bridge)
 	struct msm_dp_bridge *dp_bridge = to_dp_bridge(drm_bridge);
 	struct msm_dp *dp = dp_bridge->dp_display;
 	struct dp_display_private *dp_display;
+	u32 state;
 
 	dp_display = container_of(dp, struct dp_display_private, dp_display);
 
+	mutex_lock(&dp_display->event_mutex);
+
+	state = dp_display->hpd_state;
+	if (state != ST_DISCONNECT_PENDING && state != ST_CONNECTED) {
+		mutex_unlock(&dp_display->event_mutex);
+		return;
+	}
+
 	dp_ctrl_push_idle(dp_display->ctrl);
+	mutex_unlock(&dp_display->event_mutex);
 }
 
 void dp_bridge_post_disable(struct drm_bridge *drm_bridge)