Re: [PATCH] arch: sh: Include <linux/io.h> in dac.h

[John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>]

Hi Thomas,

On Mon, 2026-04-13 at 08:59 +0200, Thomas Zimmermann wrote:
> Hi
> 
> Am 12.04.26 um 09:35 schrieb John Paul Adrian Glaubitz:
> > Hi Thomas,
> > 
> > On Tue, 2025-10-28 at 18:07 +0100, Thomas Zimmermann wrote:
> > > Include <linux/io.h> to avoid depending on <linux/backlight.h> for
> > > including it. Declares __raw_readb() and __raw_writeb().
> > > 
> > > Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
> > > Reported-by: kernel test robot <lkp@intel.com>
> > > Closes: https://lore.kernel.org/oe-kbuild-all/202510282206.wI0HrqcK-lkp@intel.com/
> > > Fixes: 243ce64b2b37 ("backlight: Do not include <linux/fb.h> in header file")
> > > Cc: Thomas Zimmermann <tzimmermann@suse.de>
> > > Cc: Daniel Thompson (RISCstar) <danielt@kernel.org>
> > > Cc: Simona Vetter <simona.vetter@ffwll.ch>
> > > Cc: Lee Jones <lee@kernel.org>
> > > Cc: Daniel Thompson <danielt@kernel.org>
> > > Cc: Jingoo Han <jingoohan1@gmail.com>
> > > Cc: dri-devel@lists.freedesktop.org
> > > ---
> > > This is fallout from a recent cleanup of the backlight header file. I don't
> > > have the option of building or testing this change, though.
> > > ---
> > >   arch/sh/include/cpu-sh3/cpu/dac.h | 2 ++
> > >   1 file changed, 2 insertions(+)
> > > 
> > > diff --git a/arch/sh/include/cpu-sh3/cpu/dac.h b/arch/sh/include/cpu-sh3/cpu/dac.h
> > > index fd02331608a8..323ec8570bcd 100644
> > > --- a/arch/sh/include/cpu-sh3/cpu/dac.h
> > > +++ b/arch/sh/include/cpu-sh3/cpu/dac.h
> > > @@ -2,6 +2,8 @@
> > >   #ifndef __ASM_CPU_SH3_DAC_H
> > >   #define __ASM_CPU_SH3_DAC_H
> > >   
> > > +#include <linux/io.h>
> > > +
> > >   /*
> > >    * Copyright (C) 2003  Andriy Skulysh
> > >    */
> > I'm just looking at this patch again and was wondering where <linux/backlight.h> is
> > actually being pulled in on SH3. I assume this is somewhere on the driver side, no?
> 
> Oh well, it's been ages...
> 
> I've been cleaning up the plenty of places that include <linux/fb.h> and 
> <linux/backlight.h> unnecessarily. Besides the Fixes tag, presumably 
> commit df1445598758 ("backlight: hp680_bl: Do not include <linux/fb.h>") 
> is involved as well. The hp680_bl backlight driver got <linux/io.h> via 
> <linux/fb.h> via <linux/backlight.h> before including <cpu/dac.h>. With 
> fb.h gone from backlight.h gone,  dac.h should best include its 
> dependencies. Hence the patch here.

Perfect, thanks for the quick explanation! I will pick up the patch then.

Adrian

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