diff mbox series

[1/1] drm/panel: panel-simple: Add dev_err_probe if backlight could not be found

Message ID 20220621072118.513346-1-alexander.stein@ew.tq-group.com (mailing list archive)
State New, archived
Headers show
Series [1/1] drm/panel: panel-simple: Add dev_err_probe if backlight could not be found | expand

Commit Message

Alexander Stein June 21, 2022, 7:21 a.m. UTC
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>
---
 drivers/gpu/drm/panel/panel-simple.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

Comments

Sam Ravnborg June 24, 2022, 7:35 p.m. UTC | #1
On Tue, Jun 21, 2022 at 09:21:18AM +0200, Alexander Stein wrote:
> 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>
Thanks, applied to drm-misc (drm-misc-next)

	Sam
diff mbox series

Patch

diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c
index 4a2e580a2f7b..8fb1c563c96a 100644
--- a/drivers/gpu/drm/panel/panel-simple.c
+++ b/drivers/gpu/drm/panel/panel-simple.c
@@ -663,8 +663,10 @@  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);