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

[Thomas Zimmermann <tzimmermann@suse.de>]

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.

Best regards
Thomas



>
> Adrian
>

-- 
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstr. 146, 90461 Nürnberg, Germany, www.suse.com
GF: Jochen Jaser, Andrew McDonald, Werner Knoblich, (HRB 36809, AG Nürnberg)