Re: [RFC PATCH] fbdev: maxinefb: fix build issues

[Maciej W. Rozycki]

On Sun, 9 Aug 2026, Randy Dunlap wrote:

> >> --- linux-next-20260807.orig/include/video/maxinefb.h
> >> +++ linux-next-20260807/include/video/maxinefb.h
> >> @@ -13,13 +13,13 @@
> >>   /*
> >>    * IMS332 video controller register base address
> >>    */
> >> -#define MAXINEFB_IMS332_ADDRESS        KSEG1ADDR(0x1c140000)
> >> +#define MAXINEFB_IMS332_ADDRESS        CKSEG1ADDR(0x1c140000)
> >>     /*
> >>    * Begin of DECstation 5000/xx onboard framebuffer memory, default resolution
> >>    * is 1024x768x8
> >>    */
> >> -#define DS5000_xx_ONBOARD_FBMEM_START    KSEG1ADDR(0x0a000000)
> >> +#define DS5000_xx_ONBOARD_FBMEM_START    CKSEG1ADDR(0x0a000000)
> > 
> > The change looks correct, but clearly this has never been tested
> > on a 64-bit DECstation, so I'm not sure having this code being
> > now built is an improvement.

 I don't expect any issues and FWIW the Maxine does support a 64-bit CPU 
module.

> > diff --git a/drivers/video/fbdev/Kconfig b/drivers/video/fbdev/Kconfig
> > index ac9ac4287c6a..ff17afe6b8b3 100644
> > --- a/drivers/video/fbdev/Kconfig
> > +++ b/drivers/video/fbdev/Kconfig
> > @@ -1436,7 +1436,7 @@ config FB_PMAGB_B
> > 
> >  config FB_MAXINE
> >         bool "Maxine (Personal DECstation) onboard framebuffer support"
> > -       depends on (FB = y) && MACH_DECSTATION
> > +       depends on (FB = y) && MACH_DECSTATION && 32BIT
> >         select FB_IOMEM_HELPERS
> >         help
> >           Support for the onboard framebuffer (1024x768x8) in the Personal
> > ---
> > 
> > ?
> 
> I guess I'm OK with that. I'm even OK with removing the driver completely.

 No need to limit the driver to 32BIT and as I suggest in the other reply 
fixing 64BIT will best be a separate change.

> Maciej did say in https://lore.kernel.org/all/alpine.DEB.2.21.2308152255080.8596@xxxxxxxxxxxxxxxxx/
> that: "the proper way would be by using `ioremap' really.  I'll make a patch."
> [That was 15.Aug.2023.]

 Even more properly this will best be converted to a platform device and 
then resource handling will DTRT.  I do hope to get a specimen eventually, 
so I think there's no need to rush making changes on paper.

  Maciej