Thread (37 messages) 37 messages, 7 authors, 2024-02-21

Re: [PATCH 01/10] backlight: Match backlight device against struct fb_info.bl_dev

From: Javier Martinez Canillas <javierm@redhat.com>
Date: 2024-02-20 09:17:37
Also in: dri-devel, linux-input, linux-pwm

Thomas Zimmermann [off-list ref] writes:

Hello Thomas,
quoted hunk ↗ jump to hunk
Framebuffer drivers for devices with dedicated backlight are supposed
to set struct fb_info.bl_dev to the backlight's respective device. Use
the value to match backlight and framebuffer in the backlight core code.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/video/backlight/backlight.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c
index 86e1cdc8e3697..48844a4f28ad3 100644
--- a/drivers/video/backlight/backlight.c
+++ b/drivers/video/backlight/backlight.c
@@ -98,7 +98,8 @@ static int fb_notifier_callback(struct notifier_block *self,
 {
 	struct backlight_device *bd;
 	struct fb_event *evdata = data;
-	int node = evdata->info->node;
+	struct fb_info *info = evdata->info;
+	int node = info->node;
 	int fb_blank = 0;
 
 	/* If we aren't interested in this event, skip it immediately ... */
@@ -110,8 +111,12 @@ static int fb_notifier_callback(struct notifier_block *self,
 
 	if (!bd->ops)
 		goto out;
-	if (bd->ops->check_fb && !bd->ops->check_fb(bd, evdata->info))
+	else if (bd->ops->check_fb && !bd->ops->check_fb(bd, info))
 		goto out;
+#if IS_ENABLED(CONFIG_FB_BACKLIGHT)
+	else if (info->bl_dev && info->bl_dev != bd)
If the driver doesn't provide a struct backlight_ops .check_fb callback, I
think that having an info->bl_dev should be mandatory ? Or at least maybe
there should be a warning if info->bl_dev isn't set ?

The would be a driver bug, right ?

Regardless, the change makes sense to me.

Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>

-- 
Best regards,

Javier Martinez Canillas
Core Platforms
Red Hat
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