linux-kernel - [PATCH 3/4] drm/bridge: lt8912b: Manually disable HPD only if it was enabled

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Date:   Fri, 04 Aug 2023 13:48:12 +0300
From:   Tomi Valkeinen <tomi.valkeinen@...asonboard.com>
To:     Adrien Grassein <adrien.grassein@...il.com>,
        Andrzej Hajda <andrzej.hajda@...el.com>,
        Neil Armstrong <neil.armstrong@...aro.org>,
        Robert Foss <rfoss@...nel.org>,
        Laurent Pinchart <Laurent.pinchart@...asonboard.com>,
        Jonas Karlman <jonas@...boo.se>,
        Jernej Skrabec <jernej.skrabec@...il.com>,
        David Airlie <airlied@...il.com>,
        Daniel Vetter <daniel@...ll.ch>,
        Francesco Dolcini <francesco.dolcini@...adex.com>,
        Stefan Eichenberger <stefan.eichenberger@...adex.com>
Cc:     dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org,
        Tomi Valkeinen <tomi.valkeinen@...asonboard.com>
Subject: [PATCH 3/4] drm/bridge: lt8912b: Manually disable HPD only if it
 was enabled

lt8912b only calls drm_bridge_hpd_enable() if it creates a connector and
the next bridge has DRM_BRIDGE_OP_HPD set. However, when calling
drm_bridge_hpd_disable() it misses checking if a connector was created,
calling drm_bridge_hpd_disable() even if HPD was nenver enabled. I don't
see any issues causing by this wrong call, though.

Add the check to avoid wrongly calling drm_bridge_hpd_disable().

Fixes: 3b0a01a6a522 ("drm/bridge: lt8912b: Add hot plug detection")
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@...asonboard.com>
---
 drivers/gpu/drm/bridge/lontium-lt8912b.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/bridge/lontium-lt8912b.c b/drivers/gpu/drm/bridge/lontium-lt8912b.c
index 2d752e083433..9ee639e75a1c 100644
--- a/drivers/gpu/drm/bridge/lontium-lt8912b.c
+++ b/drivers/gpu/drm/bridge/lontium-lt8912b.c
@@ -587,7 +587,7 @@ static void lt8912_bridge_detach(struct drm_bridge *bridge)
 
 	lt8912_hard_power_off(lt);
 
-	if (lt->hdmi_port->ops & DRM_BRIDGE_OP_HPD)
+	if (lt->connector.dev && lt->hdmi_port->ops & DRM_BRIDGE_OP_HPD)
 		drm_bridge_hpd_disable(lt->hdmi_port);
 }
 

-- 
2.34.1