From a45b6e67150abc2d4efa28fdc0567c36c13524af Mon Sep 17 00:00:00 2001
From: Alexander Stein <alexander.stein@ew.tq-group.com>
Date: Tue, 21 Jun 2022 09:21:18 +0200
Subject: drm/panel: panel-simple: Add dev_err_probe if backlight could not be
found
Git-commit: d9e74da2f1fc42926c6ace1bc47a700f88ada696
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
If the backlight node is not enabled, this (silently) returns with
-EPROBE_DEFER. /sys/kernel/debug/devices_deferred also shows nothing
helpful:
$ cat /sys/kernel/debug/devices_deferred
display
With this patch, there is a helpful hint:
$ cat /sys/kernel/debug/devices_deferred
display panel-simple: Could not find backlight
Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220621072118.513346-1-alexander.stein@ew.tq-group.com
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
drivers/gpu/drm/panel/panel-simple.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c
index 4f15f6d1b430..ad3434550a94 100644
--- a/drivers/gpu/drm/panel/panel-simple.c
+++ b/drivers/gpu/drm/panel/panel-simple.c
@@ -675,8 +675,10 @@ static int panel_simple_probe(struct device *dev, const struct panel_desc *desc)
drm_panel_init(&panel->base, dev, &panel_simple_funcs, connector_type);
err = drm_panel_of_backlight(&panel->base);
- if (err)
+ if (err) {
+ dev_err_probe(dev, err, "Could not find backlight\n");
goto disable_pm_runtime;
+ }
drm_panel_add(&panel->base);
--
2.38.1