Re: [PATCH] m68k: Fix VGA I/O defines

Hi Thomas,

On Tue, Jan 7, 2025 at 10:59 AM Thomas Zimmermann [off-list ref] wrote:

Including m86k's <asm/raw_io.h> in vga.h on nommu platforms results
in conflicting defines with io_no.h for various I/O macros from the
__raw_read and __raw_write families. An example error is

   In file included from arch/m68k/include/asm/vga.h:12,
                 from include/video/vga.h:22,
                 from include/linux/vgaarb.h:34,
                 from drivers/video/aperture.c:12:

quoted

quoted

arch/m68k/include/asm/raw_io.h:39: warning: "__raw_readb" redefined

      39 | #define __raw_readb in_8
         |
   In file included from arch/m68k/include/asm/io.h:6,
                    from include/linux/io.h:13,
                    from include/linux/irq.h:20,
                    from include/asm-generic/hardirq.h:17,
                    from ./arch/m68k/include/generated/asm/hardirq.h:1,
                    from include/linux/hardirq.h:11,
                    from include/linux/interrupt.h:11,
                    from include/linux/trace_recursion.h:5,
                    from include/linux/ftrace.h:10,
                    from include/linux/kprobes.h:28,
                    from include/linux/kgdb.h:19,
                    from include/linux/fb.h:6,
                    from drivers/video/aperture.c:5:
   arch/m68k/include/asm/io_no.h:16: note: this is the location of the previous definition
      16 | #define __raw_readb(addr) \
         |

Include <asm/io.h>, which avoid raw_io.h on nommu platforms. Also change
the defined values of some of the read/write symbols in vga.h to
__raw_read/__raw_write as the raw_in/raw_out symbols are not generally
available.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reported-by: kernel test robot <redacted>
Closes: https://lore.kernel.org/oe-kbuild-all/202501071629.DNEswlm8-lkp@intel.com/ (local)
Fixes: 5c3f968712ce ("m68k/video: Create <asm/vga.h>")
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: linux-fbdev@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: Helge Deller <deller@gmx.de>
Cc: <redacted> # v3.5+

Thanks for your patch!

It definitely makes sense to include <asm/io.h> instead of
<asm/raw_io.h> in this file.

OK

 #endif /* CONFIG_PCI */
 #endif /* _ASM_M68K_VGA_H */

I gave it a try on various configs, and inspected the impact
(none, except for killing the warnings), so
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
i.e. will queue in the m68k tree for v6.14.

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds