Patch "drm/bridge: lt8912b: Fix bridge_detach" has been added to the 5.15-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

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

    drm/bridge: lt8912b: Fix bridge_detach

to the 5.15-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-lt8912b-fix-bridge_detach.patch
and it can be found in the queue-5.15 subdirectory.

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



commit 91da7a12a3eb0d3b19a628f1dd58c2f0e4024054
Author: Tomi Valkeinen <tomi.valkeinen@xxxxxxxxxxxxxxxx>
Date:   Fri Aug 4 13:48:10 2023 +0300

    drm/bridge: lt8912b: Fix bridge_detach
    
    [ Upstream commit 941882a0e96d245f38116e940912b404b6a93c6f ]
    
    The driver calls lt8912_bridge_detach() from its lt8912_remove()
    function. As the DRM core detaches bridges automatically, this leads to
    calling lt8912_bridge_detach() twice. The code probably has tried to
    manage the double-call with the 'is_attached' variable, but the driver
    never sets the variable to false, so its of no help.
    
    Fix the issue by dropping the call to lt8912_bridge_detach() from
    lt8912_remove(), as the DRM core will handle the detach call for us,
    and also drop the useless is_attached field.
    
    Fixes: 30e2ae943c26 ("drm/bridge: Introduce LT8912B DSI to HDMI bridge")
    Signed-off-by: Tomi Valkeinen <tomi.valkeinen@xxxxxxxxxxxxxxxx>
    Reviewed-by: Robert Foss <rfoss@xxxxxxxxxx>
    Signed-off-by: Robert Foss <rfoss@xxxxxxxxxx>
    Link: https://patchwork.freedesktop.org/patch/msgid/20230804-lt8912b-v1-1-c542692c6a2f@xxxxxxxxxxxxxxxx
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/gpu/drm/bridge/lontium-lt8912b.c b/drivers/gpu/drm/bridge/lontium-lt8912b.c
index a89e505aa3811..d435cb3ed3808 100644
--- a/drivers/gpu/drm/bridge/lontium-lt8912b.c
+++ b/drivers/gpu/drm/bridge/lontium-lt8912b.c
@@ -43,7 +43,6 @@ struct lt8912 {
 
 	u8 data_lanes;
 	bool is_power_on;
-	bool is_attached;
 };
 
 static int lt8912_write_init_config(struct lt8912 *lt)
@@ -565,8 +564,6 @@ static int lt8912_bridge_attach(struct drm_bridge *bridge,
 	if (ret)
 		goto error;
 
-	lt->is_attached = true;
-
 	return 0;
 
 error:
@@ -578,15 +575,13 @@ static void lt8912_bridge_detach(struct drm_bridge *bridge)
 {
 	struct lt8912 *lt = bridge_to_lt8912(bridge);
 
-	if (lt->is_attached) {
-		lt8912_hard_power_off(lt);
+	lt8912_hard_power_off(lt);
 
-		if (lt->hdmi_port->ops & DRM_BRIDGE_OP_HPD)
-			drm_bridge_hpd_disable(lt->hdmi_port);
+	if (lt->hdmi_port->ops & DRM_BRIDGE_OP_HPD)
+		drm_bridge_hpd_disable(lt->hdmi_port);
 
-		drm_connector_unregister(&lt->connector);
-		drm_connector_cleanup(&lt->connector);
-	}
+	drm_connector_unregister(&lt->connector);
+	drm_connector_cleanup(&lt->connector);
 }
 
 static enum drm_connector_status
@@ -746,7 +741,6 @@ static int lt8912_remove(struct i2c_client *client)
 {
 	struct lt8912 *lt = i2c_get_clientdata(client);
 
-	lt8912_bridge_detach(&lt->bridge);
 	drm_bridge_remove(&lt->bridge);
 	lt8912_free_i2c(lt);
 	lt8912_put_dt(lt);