From 4bd3d8d272499e9325c5ac3f29e0e704c62a05f1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?N=C3=ADcolas=20F=2E=20R=2E=20A=2E=20Prado?=
<nfraprado@collabora.com>
Date: Mon, 13 Jun 2022 12:37:05 -0400
Subject: drm/bridge: anx7625: Zero error variable when panel bridge not
present
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Git-commit: 3f49f7591e7150c502aa8d04354941ec2394153f
Patch-mainline: v6.0-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225 jsc#PED-2849
While parsing the DT, the anx7625 driver checks for the presence of a
panel bridge on endpoint 1. If it is missing, pdata->panel_bridge stores
the error pointer and the function returns successfully without first
cleaning that variable. This is an issue since other functions later
check for the presence of a panel bridge by testing the trueness of that
variable.
In order to ensure proper behavior, zero out pdata->panel_bridge before
returning when no panel bridge is found.
Fixes: 9e82ea0fb1df ("drm/bridge: anx7625: switch to devm_drm_of_get_bridge")
Signed-off-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220613163705.1531721-1-nfraprado@collabora.com
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
drivers/gpu/drm/bridge/analogix/anx7625.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/bridge/analogix/anx7625.c b/drivers/gpu/drm/bridge/analogix/anx7625.c
index bbdca16db0d6..f08f3307079e 100644
--- a/drivers/gpu/drm/bridge/analogix/anx7625.c
+++ b/drivers/gpu/drm/bridge/analogix/anx7625.c
@@ -1658,8 +1658,10 @@ static int anx7625_parse_dt(struct device *dev,
pdata->panel_bridge = devm_drm_of_get_bridge(dev, np, 1, 0);
if (IS_ERR(pdata->panel_bridge)) {
- if (PTR_ERR(pdata->panel_bridge) == -ENODEV)
+ if (PTR_ERR(pdata->panel_bridge) == -ENODEV) {
+ pdata->panel_bridge = NULL;
return 0;
+ }
return PTR_ERR(pdata->panel_bridge);
}
--
2.38.1