Re: [PATCH v3 35/38] video: handle HAS_IOPORT dependencies

Ville Syrjälä
2023-03-15T10:21:33Z

On Wed, Mar 15, 2023 at 09:16:50AM +0100, Geert Uytterhoeven wrote:
> Hi Niklas,
>
> On Tue, Mar 14, 2023 at 1:13 PM Niklas Schnelle <schnelle@linux.ibm.com> wrote:
> > In a future patch HAS_IOPORT=n will result in inb()/outb() and friends
> > not being declared. We thus need to add HAS_IOPORT as dependency for
> > those drivers using them and guard inline code in headers.
> >
> > Co-developed-by: Arnd Bergmann <arnd@kernel.org>
> > Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
>
> Thanks for your patch!
>
> > --- a/drivers/video/fbdev/Kconfig
> > +++ b/drivers/video/fbdev/Kconfig
>
> > @@ -1284,7 +1285,7 @@ config FB_ATY128_BACKLIGHT
> >
> > config FB_ATY
> > tristate "ATI Mach64 display support" if PCI || ATARI
> > - depends on FB && !SPARC32
> > + depends on FB && HAS_IOPORT && !SPARC32
>
> On Atari, this works without ATARI_ROM_ISA, hence it must not depend
> on HAS_IOPORT.
> The only call to inb() is inside a section protected by #ifdef
> CONFIG_PCI. So:

That piece of code is a nop anyway. We immediately overwrite
clk_wr_offset with a hardcoded selection after the register reads.
So if you nuke that nop code then no IOPORT dependency required
at all.

>
> depends on FB && !SPARC32
> depends on ATARI || HAS_IOPORT
>
> > select FB_CFB_FILLRECT
> > select FB_CFB_COPYAREA
> > select FB_CFB_IMAGEBLIT
>
> 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

--
Ville Syrjälä
Intel