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

["Philippe Mathieu-Daudé" <philmd@oss.qualcomm.com>]

Hi Randy,

On 10/8/26 01:48, Randy Dunlap wrote:
> This is all ancient source code from the beginning of git time.
> Now builds cleanly on 32-bit and 64-bit MACH_DECSTATION.
> 
> Fixes these build errors/warnings:
> 
> ../drivers/video/fbdev/maxinefb.c:64:6: warning: no previous prototype for 'maxinefb_ims332_write_register' [-Wmissing-prototypes]
>     64 | void maxinefb_ims332_write_register(int regno, register unsigned int val)
>        |      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 
> In file included from ../drivers/video/fbdev/maxinefb.c:34:
> ../drivers/video/fbdev/maxinefb.c: In function 'maxinefb_ims332_write_register':
> ../include/video/maxinefb.h:16:41: error: implicit declaration of function 'KSEG1ADDR'; did you mean 'CKSEG1ADDR'? [-Wimplicit-function-declaration]
>     16 | #define MAXINEFB_IMS332_ADDRESS         KSEG1ADDR(0x1c140000)
>        |                                         ^~~~~~~~~
> ../drivers/video/fbdev/maxinefb.c:66:49: note: in expansion of macro 'MAXINEFB_IMS332_ADDRESS'
>     66 |         register unsigned char *regs = (char *) MAXINEFB_IMS332_ADDRESS;
>        |                                                 ^~~~~~~~~~~~~~~~~~~~~~~
> ../drivers/video/fbdev/maxinefb.c:66:40: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
>     66 |         register unsigned char *regs = (char *) MAXINEFB_IMS332_ADDRESS;
>        |                                        ^
> ../drivers/video/fbdev/maxinefb.c: At top level:
> ../drivers/video/fbdev/maxinefb.c:74:14: warning: no previous prototype for 'maxinefb_ims332_read_register' [-Wmissing-prototypes]
>     74 | unsigned int maxinefb_ims332_read_register(int regno)
>        |              ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> ../drivers/video/fbdev/maxinefb.c: At top level:
> ../drivers/video/fbdev/maxinefb.c:74:21: warning: 'maxinefb_ims332_read_register' defined but not used [-Wunused-function]
>     74 | static unsigned int maxinefb_ims332_read_register(int regno)
>        |                     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> ../drivers/video/fbdev/maxinefb.c: In function 'maxinefb_ims332_read_register':
> ../drivers/video/fbdev/maxinefb.c:76:40: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
>     76 |         register unsigned char *regs = (char *) MAXINEFB_IMS332_ADDRESS;
>        |                                        ^
> ../drivers/video/fbdev/maxinefb.c: At top level:
> ../drivers/video/fbdev/maxinefb.c:114:12: warning: no previous prototype for 'maxinefb_init' [-Wmissing-prototypes]
>    114 | int __init maxinefb_init(void)
>        |            ^~~~~~~~~~~~~
> In file included from ../drivers/video/fbdev/maxinefb.c:34:
> ../drivers/video/fbdev/maxinefb.c: In function 'maxinefb_init':
> ../include/video/maxinefb.h:22:41: error: implicit declaration of function 'KSEG1ADDR'; did you mean 'CKSEG1ADDR'? [-Wimplicit-function-declaration]
>     22 | #define DS5000_xx_ONBOARD_FBMEM_START   KSEG1ADDR(0x0a000000)
>        |                                         ^~~~~~~~~
> ../drivers/video/fbdev/maxinefb.c:119:20: note: in expansion of macro 'DS5000_xx_ONBOARD_FBMEM_START'
>    119 |         fb_start = DS5000_xx_ONBOARD_FBMEM_START;
>        |                    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 
> Suggested-by: "Maciej W. Rozycki" <macro@orcam.me.uk> # for s/KSEG1ADDR/CKSEG1ADDR/
> Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
> ---
> Cc: "Maciej W. Rozycki" <macro@orcam.me.uk>
> Cc: Helge Deller <deller@gmx.de>
> Cc: linux-fbdev@vger.kernel.org
> Cc: dri-devel@lists.freedesktop.org
> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
> Cc: linux-mips@vger.kernel.org
> 
>   drivers/video/fbdev/maxinefb.c |   17 ++---------------
>   include/video/maxinefb.h       |    4 ++--
>   2 files changed, 4 insertions(+), 17 deletions(-)
> 
> --- linux-next-20260807.orig/drivers/video/fbdev/maxinefb.c
> +++ linux-next-20260807/drivers/video/fbdev/maxinefb.c
> @@ -61,7 +61,7 @@ static struct fb_fix_screeninfo maxinefb
>   
>   /* Handle the funny Inmos RamDAC/video controller ... */
>   
> -void maxinefb_ims332_write_register(int regno, register unsigned int val)
> +static void maxinefb_ims332_write_register(int regno, register unsigned int val)
>   {
>   	register unsigned char *regs = (char *) MAXINEFB_IMS332_ADDRESS;
>   	unsigned char *wptr;
> @@ -71,19 +71,6 @@ void maxinefb_ims332_write_register(int
>   	*((volatile unsigned short *) (wptr)) = val;
>   }
>   
> -unsigned int maxinefb_ims332_read_register(int regno)
> -{
> -	register unsigned char *regs = (char *) MAXINEFB_IMS332_ADDRESS;
> -	unsigned char *rptr;
> -	register unsigned int j, k;
> -
> -	rptr = regs + 0x80000 + (regno << 4);
> -	j = *((volatile unsigned short *) rptr);
> -	k = *((volatile unsigned short *) regs);
> -
> -	return (j & 0xffff) | ((k & 0xff00) << 8);
> -}
> -
>   /* Set the palette */
>   static int maxinefb_setcolreg(unsigned regno, unsigned red, unsigned green,
>   			      unsigned blue, unsigned transp, struct fb_info *info)
> @@ -111,7 +98,7 @@ static const struct fb_ops maxinefb_ops
>   	.fb_setcolreg	= maxinefb_setcolreg,
>   };
>   
> -int __init maxinefb_init(void)
> +static int __init maxinefb_init(void)
>   {
>   	unsigned long fboff;
>   	unsigned long fb_start;
> --- 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.

What about:

-- >8 --
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
---

?

Regards,

Phil.