Re: [PATCH 02/30] backlight/gpio_backlight: Compare against struct fb_info.device

On Tue, Jun 06, 2023 at 09:24:48AM +0200, Thomas Zimmermann wrote:

Hi

Am 05.06.23 um 22:19 schrieb Ruhl, Michael J:

quoted

quoted

-----Original Message-----
From: dri-devel <redacted> On Behalf Of
Thomas Zimmermann
Sent: Monday, June 5, 2023 10:48 AM
To: daniel@ffwll.ch; javierm@redhat.com; sam@ravnborg.org;
deller@gmx.de; geert+renesas@glider.be; lee@kernel.org;
daniel.thompson@linaro.org; jingoohan1@gmail.com
Cc: linux-fbdev@vger.kernel.org; Rich Felker <dalias@libc.org>; linux-
sh@vger.kernel.org; linux-staging@lists.linux.dev; dri-
devel@lists.freedesktop.org; Thomas Zimmermann
[off-list ref]; John Paul Adrian Glaubitz <glaubitz@physik.fu-
berlin.de>; linux-omap@vger.kernel.org
Subject: [PATCH 02/30] backlight/gpio_backlight: Compare against struct
fb_info.device

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.

I only see a rename from fbdev  to dev...

Is there missing code?

As Sam said, the compare operation used the wrong device from fb_info.

I also changed the naming of a few fields in these backlight drivers. I
could move these renames into a separate patch if that makes things easier
for reviewers.

quoted

Would  a fixes: be useful?

That would be commit 8b770e3c9824 ("backlight: Add GPIO-based backlight
driver") from 2013. Maybe a bit old already, but I can surely add it.

Don't add the Fixes tag to this one because it doesn't fix anything, it
just renames stuff.  The real fix is later?  To be honest, it was kind
of difficult to see where the actual fix was.

Fixes tags for old code is fine...  I like to know why bugs are
introduced.  Was it adding a feature or part of fix for something else
or a cleanup?

regards,
dan carpenter