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

Hi Randy,

On 10/8/26 01:48, Randy Dunlap wrote:

quoted

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 <redacted>
---
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
---

?