[PATCH] fbdev: fbmem: mark get_fb_unmapped_area() static

[Geert Uytterhoeven]

Hi Helge,

On Fri, May 19, 2023 at 4:37 PM Helge Deller <deller at gmx.de> wrote:
> * Geert Uytterhoeven <geert at linux-m68k.org>:
> > On Tue, May 16, 2023 at 10:23 PM Arnd Bergmann <arnd at kernel.org> wrote:
> > > From: Arnd Bergmann <arnd at arndb.de>
> > >
> > > There is a global function with this name on sparc, but no
> > > global declaration:
> > >
> > > drivers/video/fbdev/core/fbmem.c:1469:15: error: no previous prototype for 'get_fb_unmapped_area'
> > >
> > > Make the generic definition static to avoid this warning. On
> > > sparc, this is never seen.
> > >
> > > Signed-off-by: Arnd Bergmann <arnd at arndb.de>
> >
> > > --- a/drivers/video/fbdev/core/fbmem.c
> > > +++ b/drivers/video/fbdev/core/fbmem.c
> > > @@ -1468,7 +1468,7 @@ __releases(&info->lock)
> > >  }
> > >
> > >  #if defined(CONFIG_FB_PROVIDE_GET_FB_UNMAPPED_AREA) && !defined(CONFIG_MMU)
> > > -unsigned long get_fb_unmapped_area(struct file *filp,
> > > +static unsigned long get_fb_unmapped_area(struct file *filp,
> > >                                    unsigned long addr, unsigned long len,
> > >                                    unsigned long pgoff, unsigned long flags)
> > >  {
> >
> > LGTM, as this is unrelated to the SPARC function, and SPARC does
> > not support nommu (yet? ;-)
> >
> > drivers/video/fbdev/Kconfig:config FB_PROVIDE_GET_FB_UNMAPPED_AREA
> > drivers/video/fbdev/Kconfig-    bool
> > drivers/video/fbdev/Kconfig-    depends on FB
> > drivers/video/fbdev/Kconfig-    help
> > drivers/video/fbdev/Kconfig-      Allow generic frame-buffer to
> > provide get_fb_unmapped_area
> > drivers/video/fbdev/Kconfig-      function.
> >
> > Probably you want to update this help text, too. E.g.
> > "to provide shareable character device support on nommu"?
>
> I've added Geerts suggestions and made it dependend on !MMU.
>
> Applied to fbdev git tree as below.
>
> Thanks!
> Helge
>
>
> From 9adfa68ca0ddd63007cdce60a8ffcb493bb30d97 Mon Sep 17 00:00:00 2001
> From: Arnd Bergmann <arnd at arndb.de>
> Subject: [PATCH] fbdev: fbmem: mark get_fb_unmapped_area() static
>
> There is a global function with this name on sparc, but no
> global declaration:
>
> drivers/video/fbdev/core/fbmem.c:1469:15: error: no previous prototype for 'get_fb_unmapped_area'
>
> Make the generic definition static to avoid this warning. On
> sparc, this is never seen.
>
> Edit by Helge:
> Update Kconfig text as suggested by Geert Uytterhoeven and make it dependend on
> !MMU.
>
> Signed-off-by: Arnd Bergmann <arnd at arndb.de>
> Signed-off-by: Helge Deller <deller at gmx.de>
>
> diff --git a/drivers/video/fbdev/Kconfig b/drivers/video/fbdev/Kconfig
> index 96e91570cdd3..1688875a07de 100644
> --- a/drivers/video/fbdev/Kconfig
> +++ b/drivers/video/fbdev/Kconfig
> @@ -121,10 +121,10 @@ config FB_SYS_IMAGEBLIT
>
>  config FB_PROVIDE_GET_FB_UNMAPPED_AREA
>         bool
> -       depends on FB
> +       depends on FB && !MMU

I expect this to cause a Kconfig warning when enabling DRM_STM
with MMU=y (e.g. multi_v7_defconfig).
ARCH_STM32 seems to support both MMU=y and MMU=n.

>         help
>           Allow generic frame-buffer to provide get_fb_unmapped_area
> -         function.
> +         function to provide shareable character device support on nommu.
>

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at 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