backlight/gpio_backlight: Compare against struct fb_info.device

commit 7b91d017f77c1bda56f27c2f4bbb70de7c6eca08 upstream.

Struct gpio_backlight_platform_data refers to a platform device within
the Linux device hierarchy. The test in gpio_backlight_check_fb()
compares it against the fbdev device in struct fb_info.dev, which
is different. Fix the test by comparing to struct fb_info.device.

Fixes a bug in the backlight driver and prepares fbdev for making
struct fb_info.dev optional.

v2:
	* move renames into separate patch (Javier, Sam, Michael)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Fixes: 8b770e3c9824 ("backlight: Add GPIO-based backlight driver")
Cc: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Cc: Rich Felker <dalias@libc.org>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Lee Jones <lee@kernel.org>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Jingoo Han <jingoohan1@gmail.com>
Cc: linux-sh@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: <stable@vger.kernel.org> # v3.12+
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230613110953.24176-4-tzimmermann@suse.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/video/backlight/gpio_backlight.c b/drivers/video/backlight/gpio_backlight.c
index 6f78d928f054a11e4ab1e5cb1aeb977ee458867c..5c5c99f7979e35c7165cd0643ec4565120db887b 100644 (file)
--- a/drivers/video/backlight/gpio_backlight.c
+++ b/drivers/video/backlight/gpio_backlight.c
@@ -35,7 +35,7 @@ static int gpio_backlight_check_fb(struct backlight_device *bl,
 {
        struct gpio_backlight *gbl = bl_get_data(bl);
 
-       return gbl->fbdev == NULL || gbl->fbdev == info->dev;
+       return gbl->fbdev == NULL || gbl->fbdev == info->device;
 }
 
 static const struct backlight_ops gpio_backlight_ops = {