Re: [PATCH] powerpc: include linux/backlight.h from asm/backlight.h

[Thomas Zimmermann <tzimmermann@xxxxxxx>]

Hi

Am 05.03.24 um 01:36 schrieb Michael Ellerman:
> Christophe Leroy <christophe.leroy@xxxxxxxxxx> writes:
> > Le 04/03/2024 à 11:32, Thomas Zimmermann a écrit :
> > > Hi
> > >
> > > Am 04.03.24 um 10:55 schrieb Jani Nikula:
> > > > Removal of the backlight include from fb.h uncovered an implicit
> > > > dependency in powerpc asm/backlight.h. Add the explicit include.
> > > >
> > > > Reported-by: Naresh Kamboju <naresh.kamboju@xxxxxxxxxx>
> > > > Closes:
> > > > https://lore.kernel.org/r/CA+G9fYsAk5TbqqxFC2W4oHLGA0CbTHMxbeq8QayFXTU75YiueA@xxxxxxxxxxxxxx
> > > > Fixes: 11b4eedfc87d ("fbdev: Do not include <linux/backlight.h> in
> > > > header")
> > > > Cc: Thomas Zimmermann <tzimmermann@xxxxxxx>
> > > > Cc: Helge Deller <deller@xxxxxx>
> > > > Cc: linux-fbdev@xxxxxxxxxxxxxxx
> > > > Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx>
> > > >
> > > > ---
> > > >
> > > > Not even compile tested!
> > > That's one of the cases that's hard to catch unless you get the config
> > > right.
> > >
> > > > ---
> > > >    arch/powerpc/include/asm/backlight.h | 1 +
> > > >    1 file changed, 1 insertion(+)
> > > >
> > > > diff --git a/arch/powerpc/include/asm/backlight.h
> > > > b/arch/powerpc/include/asm/backlight.h
> > > > index 1b5eab62ed04..275d5bb9aa04 100644
> > > > --- a/arch/powerpc/include/asm/backlight.h
> > > > +++ b/arch/powerpc/include/asm/backlight.h
> > > > @@ -10,6 +10,7 @@
> > > >    #define __ASM_POWERPC_BACKLIGHT_H
> > > >    #ifdef __KERNEL__
> > > > +#include <linux/backlight.h>
> > > Thanks, but I think this should go directly into chipsfb.c. I would have
> > > provided a patch already, if our mail server didn't have issues this
> > > morning. Let me try again.
> > asm/backlight.h needs it for struct backlight_device
> >
> > At least if you don't want to include linux/backlight.h in
> > asm/backlight.h, then you need a forward declaration of struct
> > backlight_device;
> It's preferable for asm headers not to include linux headers (to avoid
> loops), so a forward declaration would be better IMHO.

The asm header shouldn't include <linux/fb.h> either. I'll send an 
update to my patch to clean up everything.

Best regards
Thomas

> cheers

--
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nuernberg, Germany
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