* [RFC PATCH] fbdev: maxinefb: fix build issues
@ 2026-08-09 23:48 Randy Dunlap
2026-08-10 0:02 ` sashiko-bot
2026-08-10 3:24 ` Philippe Mathieu-Daudé
0 siblings, 2 replies; 5+ messages in thread
From: Randy Dunlap @ 2026-08-09 23:48 UTC (permalink / raw)
To: linux-kernel
Cc: Randy Dunlap, Maciej W. Rozycki, Helge Deller, linux-fbdev,
dri-devel, Thomas Bogendoerfer, linux-mips
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 IMS 332 video controller used in the DECstation 5000/xx series
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [RFC PATCH] fbdev: maxinefb: fix build issues
2026-08-09 23:48 [RFC PATCH] fbdev: maxinefb: fix build issues Randy Dunlap
@ 2026-08-10 0:02 ` sashiko-bot
2026-08-10 0:27 ` Randy Dunlap
2026-08-10 3:24 ` Philippe Mathieu-Daudé
1 sibling, 1 reply; 5+ messages in thread
From: sashiko-bot @ 2026-08-10 0:02 UTC (permalink / raw)
To: Randy Dunlap; +Cc: dri-devel
Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:
Pre-existing issues:
- [High] Initialization function returns positive value `1` on failure, breaking module load semantics and causing subsequent `registered_fb` array corruption on unload.
- [High] `maxinefb_fix.smem_start` is initialized with a virtual address (`CKSEG1ADDR`) instead of the hardware physical address, breaking user-space `mmap()`.
--
--- Patch [1]: [RFC PATCH] fbdev: maxinefb: fix build issues ---
commit e391418fa2f21f8c420eccb513c031674ef184c6
Author: Randy Dunlap <rdunlap@infradead.org>
fbdev: maxinefb: fix build issues
This commit fixes build errors and warnings for the maxinefb driver on
32-bit and 64-bit MACH_DECSTATION. It updates KSEG1ADDR to CKSEG1ADDR and
adds the static keyword to missing prototypes.
> diff --git a/drivers/video/fbdev/maxinefb.c b/drivers/video/fbdev/maxinefb.c
> index 52528eb4dfb41..8aa1389e2d4c8 100644
> --- a/drivers/video/fbdev/maxinefb.c
> +++ b/drivers/video/fbdev/maxinefb.c
[ ... ]
> @@ -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)
[Severity: High]
This is a pre-existing issue, but does returning 1 on failure in this function
cause issues with module load semantics?
In maxinefb_init():
if (register_framebuffer(&fb_info) < 0)
return 1;
If register_framebuffer() fails, returning a positive integer causes the kernel
to treat the module as successfully loaded because the module init framework
expects negative error codes for failure.
Later, when the module is unloaded, maxinefb_exit() calls
unregister_framebuffer() on the unregistered fb_info. Since it was never
successfully registered, its node field is 0.
Does this cause the generic do_unregister_framebuffer() to blindly execute
registered_fb[0] = NULL, corrupting the kernel's framebuffer state by deleting
the reference to whatever valid framebuffer occupied node 0?
> diff --git a/include/video/maxinefb.h b/include/video/maxinefb.h
> index 6aeb4acca2bdb..2b66b32f355cf 100644
> --- a/include/video/maxinefb.h
> +++ b/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)
[Severity: High]
This is a pre-existing issue, but does assigning a virtual address to
maxinefb_fix.smem_start break user-space mmap()?
In maxinefb_init():
fb_start = DS5000_xx_ONBOARD_FBMEM_START;
...
maxinefb_fix.smem_start = fb_start;
The smem_start field is passed to vm_iomap_memory() by the generic framebuffer
mmap handler (fb_mmap()). Because vm_iomap_memory() strictly expects a physical
address, does passing a KSEG1 virtual address set up user-space page tables
pointing to an invalid physical address?
This could trigger an invalid physical memory access and a kernel panic when
user-space accesses the mapped memory.
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260809234810.982500-1-rdunlap@infradead.org?part=1
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [RFC PATCH] fbdev: maxinefb: fix build issues
2026-08-10 0:02 ` sashiko-bot
@ 2026-08-10 0:27 ` Randy Dunlap
0 siblings, 0 replies; 5+ messages in thread
From: Randy Dunlap @ 2026-08-10 0:27 UTC (permalink / raw)
To: sashiko-reviews
Cc: dri-devel, Maciej W. Rozycki, Helge Deller, linux-fbdev,
linux-mips, Thomas Bogendoerfer
[adding Cc:s]
On 8/9/26 5:02 PM, sashiko-bot@kernel.org wrote:
> Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:
>
> Pre-existing issues:
> - [High] Initialization function returns positive value `1` on failure, breaking module load semantics and causing subsequent `registered_fb` array corruption on unload.
> - [High] `maxinefb_fix.smem_start` is initialized with a virtual address (`CKSEG1ADDR`) instead of the hardware physical address, breaking user-space `mmap()`.
> --
>
> --- Patch [1]: [RFC PATCH] fbdev: maxinefb: fix build issues ---
> commit e391418fa2f21f8c420eccb513c031674ef184c6
> Author: Randy Dunlap <rdunlap@infradead.org>
>
> fbdev: maxinefb: fix build issues
>
> This commit fixes build errors and warnings for the maxinefb driver on
> 32-bit and 64-bit MACH_DECSTATION. It updates KSEG1ADDR to CKSEG1ADDR and
> adds the static keyword to missing prototypes.
>
>> diff --git a/drivers/video/fbdev/maxinefb.c b/drivers/video/fbdev/maxinefb.c
>> index 52528eb4dfb41..8aa1389e2d4c8 100644
>> --- a/drivers/video/fbdev/maxinefb.c
>> +++ b/drivers/video/fbdev/maxinefb.c
> [ ... ]
>> @@ -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)
>
> [Severity: High]
> This is a pre-existing issue, but does returning 1 on failure in this function
> cause issues with module load semantics?
>
> In maxinefb_init():
>
> if (register_framebuffer(&fb_info) < 0)
> return 1;
>
> If register_framebuffer() fails, returning a positive integer causes the kernel
> to treat the module as successfully loaded because the module init framework
> expects negative error codes for failure.
Ack. I'll change that.
> Later, when the module is unloaded, maxinefb_exit() calls
> unregister_framebuffer() on the unregistered fb_info. Since it was never
> successfully registered, its node field is 0.
>
> Does this cause the generic do_unregister_framebuffer() to blindly execute
> registered_fb[0] = NULL, corrupting the kernel's framebuffer state by deleting
> the reference to whatever valid framebuffer occupied node 0?
>
>> diff --git a/include/video/maxinefb.h b/include/video/maxinefb.h
>> index 6aeb4acca2bdb..2b66b32f355cf 100644
>> --- a/include/video/maxinefb.h
>> +++ b/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)
Maciej or anyone:
can you comment of this, please?
> [Severity: High]
> This is a pre-existing issue, but does assigning a virtual address to
> maxinefb_fix.smem_start break user-space mmap()?
>
> In maxinefb_init():
>
> fb_start = DS5000_xx_ONBOARD_FBMEM_START;
> ...
> maxinefb_fix.smem_start = fb_start;
>
> The smem_start field is passed to vm_iomap_memory() by the generic framebuffer
> mmap handler (fb_mmap()). Because vm_iomap_memory() strictly expects a physical
> address, does passing a KSEG1 virtual address set up user-space page tables
> pointing to an invalid physical address?
>
> This could trigger an invalid physical memory access and a kernel panic when
> user-space accesses the mapped memory.
>
--
~Randy
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [RFC PATCH] fbdev: maxinefb: fix build issues
2026-08-09 23:48 [RFC PATCH] fbdev: maxinefb: fix build issues Randy Dunlap
2026-08-10 0:02 ` sashiko-bot
@ 2026-08-10 3:24 ` Philippe Mathieu-Daudé
2026-08-10 3:29 ` Randy Dunlap
1 sibling, 1 reply; 5+ messages in thread
From: Philippe Mathieu-Daudé @ 2026-08-10 3:24 UTC (permalink / raw)
To: Randy Dunlap, linux-kernel
Cc: Maciej W. Rozycki, Helge Deller, linux-fbdev, dri-devel,
Thomas Bogendoerfer, linux-mips
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.
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [RFC PATCH] fbdev: maxinefb: fix build issues
2026-08-10 3:24 ` Philippe Mathieu-Daudé
@ 2026-08-10 3:29 ` Randy Dunlap
0 siblings, 0 replies; 5+ messages in thread
From: Randy Dunlap @ 2026-08-10 3:29 UTC (permalink / raw)
To: Philippe Mathieu-Daudé, linux-kernel
Cc: Maciej W. Rozycki, Helge Deller, linux-fbdev, dri-devel,
Thomas Bogendoerfer, linux-mips
Hi,
On 8/9/26 8:24 PM, Philippe Mathieu-Daudé wrote:
> 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
> ---
>
> ?
I guess I'm OK with that. I'm even OK with removing the driver completely.
Maciej did say in https://lore.kernel.org/all/alpine.DEB.2.21.2308152255080.8596@angie.orcam.me.uk/
that: "the proper way would be by using `ioremap' really. I'll make a patch."
[That was 15.Aug.2023.]
--
~Randy
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2026-08-10 3:29 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-08-09 23:48 [RFC PATCH] fbdev: maxinefb: fix build issues Randy Dunlap
2026-08-10 0:02 ` sashiko-bot
2026-08-10 0:27 ` Randy Dunlap
2026-08-10 3:24 ` Philippe Mathieu-Daudé
2026-08-10 3:29 ` Randy Dunlap
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