Patch "drm/bridge: anx7625: Ensure bridge is suspended in disable()" has been added to the 6.6-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    drm/bridge: anx7625: Ensure bridge is suspended in disable()

to the 6.6-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     drm-bridge-anx7625-ensure-bridge-is-suspended-in-dis.patch
and it can be found in the queue-6.6 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 665b1635480dff4abc43844c85e8d90541b9dd8d
Author: Hsin-Yi Wang <hsinyi@xxxxxxxxxxxx>
Date:   Wed Jan 17 17:58:14 2024 -0800

    drm/bridge: anx7625: Ensure bridge is suspended in disable()
    
    [ Upstream commit 4d5b7daa3c610af3f322ad1e91fc0c752ff32f0e ]
    
    Similar to commit 26db46bc9c67 ("drm/bridge: parade-ps8640: Ensure bridge
    is suspended in .post_disable()"). Add a mutex to ensure that aux transfer
    won't race with atomic_disable by holding the PM reference and prevent
    the bridge from suspend.
    
    Also we need to use pm_runtime_put_sync_suspend() to suspend the bridge
    instead of idle with pm_runtime_put_sync().
    
    Fixes: 3203e497eb76 ("drm/bridge: anx7625: Synchronously run runtime suspend.")
    Fixes: adca62ec370c ("drm/bridge: anx7625: Support reading edid through aux channel")
    Signed-off-by: Hsin-Yi Wang <hsinyi@xxxxxxxxxxxx>
    Tested-by: Xuxin Xiong <xuxinxiong@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx>
    Reviewed-by: Pin-yen Lin <treapking@xxxxxxxxxxxx>
    Reviewed-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
    Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
    Link: https://patchwork.freedesktop.org/patch/msgid/20240118015916.2296741-1-hsinyi@xxxxxxxxxxxx
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/gpu/drm/bridge/analogix/anx7625.c b/drivers/gpu/drm/bridge/analogix/anx7625.c
index 51abe42c639e..5168628f11cf 100644
--- a/drivers/gpu/drm/bridge/analogix/anx7625.c
+++ b/drivers/gpu/drm/bridge/analogix/anx7625.c
@@ -1741,6 +1741,7 @@ static ssize_t anx7625_aux_transfer(struct drm_dp_aux *aux,
 	u8 request = msg->request & ~DP_AUX_I2C_MOT;
 	int ret = 0;
 
+	mutex_lock(&ctx->aux_lock);
 	pm_runtime_get_sync(dev);
 	msg->reply = 0;
 	switch (request) {
@@ -1757,6 +1758,7 @@ static ssize_t anx7625_aux_transfer(struct drm_dp_aux *aux,
 					msg->size, msg->buffer);
 	pm_runtime_mark_last_busy(dev);
 	pm_runtime_put_autosuspend(dev);
+	mutex_unlock(&ctx->aux_lock);
 
 	return ret;
 }
@@ -2453,7 +2455,9 @@ static void anx7625_bridge_atomic_disable(struct drm_bridge *bridge,
 	ctx->connector = NULL;
 	anx7625_dp_stop(ctx);
 
-	pm_runtime_put_sync(dev);
+	mutex_lock(&ctx->aux_lock);
+	pm_runtime_put_sync_suspend(dev);
+	mutex_unlock(&ctx->aux_lock);
 }
 
 static enum drm_connector_status
@@ -2647,6 +2651,7 @@ static int anx7625_i2c_probe(struct i2c_client *client)
 
 	mutex_init(&platform->lock);
 	mutex_init(&platform->hdcp_wq_lock);
+	mutex_init(&platform->aux_lock);
 
 	INIT_DELAYED_WORK(&platform->hdcp_work, hdcp_check_work_func);
 	platform->hdcp_workqueue = create_workqueue("hdcp workqueue");
diff --git a/drivers/gpu/drm/bridge/analogix/anx7625.h b/drivers/gpu/drm/bridge/analogix/anx7625.h
index 5af819611ebc..80d3fb4e985f 100644
--- a/drivers/gpu/drm/bridge/analogix/anx7625.h
+++ b/drivers/gpu/drm/bridge/analogix/anx7625.h
@@ -471,6 +471,8 @@ struct anx7625_data {
 	struct workqueue_struct *hdcp_workqueue;
 	/* Lock for hdcp work queue */
 	struct mutex hdcp_wq_lock;
+	/* Lock for aux transfer and disable */
+	struct mutex aux_lock;
 	char edid_block;
 	struct display_timing dt;
 	u8 display_timing_valid;