Re: [Linux-fbdev-devel] Re: [PATCH] fbdev: Fix IO access in rivafb

From: Linus Torvalds
Date: Fri Nov 12 2004 - 11:01:54 EST




On Fri, 12 Nov 2004, Guido Guenther wrote:
>
> Doesn't work for me. This one works:
>
> diff -u -u linux-2.6.10-rc1-mm5.orig/drivers/video/riva/riva_hw.h linux-2.6.10-rc1-mm5/drivers/video/riva/riva_hw.h
> --- linux-2.6.10-rc1-mm5.orig/drivers/video/riva/riva_hw.h 2004-11-12 13:42:54.000000000 +0100
> +++ linux-2.6.10-rc1-mm5/drivers/video/riva/riva_hw.h 2004-11-12 13:47:29.400807920 +0100
> @@ -75,12 +75,12 @@
> */
> #include <asm/io.h>
>
> -#define NV_WR08(p,i,d) (__raw_writeb((d), (void __iomem *)(p) + (i)))
> -#define NV_RD08(p,i) (__raw_readb((void __iomem *)(p) + (i)))
> -#define NV_WR16(p,i,d) (__raw_writew((d), (void __iomem *)(p) + (i)))
> -#define NV_RD16(p,i) (__raw_readw((void __iomem *)(p) + (i)))
> -#define NV_WR32(p,i,d) (__raw_writel((d), (void __iomem *)(p) + (i)))
> -#define NV_RD32(p,i) (__raw_readl((void __iomem *)(p) + (i)))
> +#define NV_WR08(p,i,d) (writeb((d), (u8 __iomem *)(p) + (i)))
> +#define NV_RD08(p,i) (readb((u8 __iomem *)(p) + (i)))
> +#define NV_WR16(p,i,d) (__raw_writew((d), (u16 __iomem *)(p) + (i)/2))
> +#define NV_RD16(p,i) (__raw_readw((u16 __iomem *)(p) + (i)/2))
> +#define NV_WR32(p,i,d) (__raw_writel((d), (u32 __iomem *)(p) + (i)/4))
> +#define NV_RD32(p,i) (__raw_readl((u32 __iomem *)(p) + (i)/4))

Can you please try without the broken "u16" and "(i/2)" things (and u32
and i/4)? They really should not be needed, unless something is
_seriously_ broken. The only thing they do is the automatically align the
reference - and quite frankly, it looks like anybody passing an unaligned
register offset is _quite_ buggy.

IOW, it would seem that the real difference is the "__raw_writeb" vs
"writeb". Can you test just that change?

> #define VGA_WR08(p,i,d) NV_WR08(p,i,d)
> #define VGA_RD08(p,i) NV_RD08(p,i)
>
> Interesting enough this one doesn't (only differenc in NV_{WR,RW}08:
>
> diff -u -u linux-2.6.10-rc1-mm5.orig/drivers/video/riva/riva_hw.h linux-2.6.10-rc1-mm5/drivers/video/riva/riva_hw.h
> --- linux-2.6.10-rc1-mm5.orig/drivers/video/riva/riva_hw.h 2004-11-12 13:42:54.000000000 +0100
> +++ linux-2.6.10-rc1-mm5/drivers/video/riva/riva_hw.h 2004-11-12 13:47:29.400807920 +0100
> @@ -75,12 +75,12 @@
> */
> #include <asm/io.h>
>
> -#define NV_WR08(p,i,d) (__raw_writeb((d), (void __iomem *)(p) + (i)))
> -#define NV_RD08(p,i) (__raw_readb((void __iomem *)(p) + (i)))
> -#define NV_WR16(p,i,d) (__raw_writew((d), (void __iomem *)(p) + (i)))
> -#define NV_RD16(p,i) (__raw_readw((void __iomem *)(p) + (i)))
> -#define NV_WR32(p,i,d) (__raw_writel((d), (void __iomem *)(p) + (i)))
> -#define NV_RD32(p,i) (__raw_readl((void __iomem *)(p) + (i)))
> +#define NV_WR08(p,i,d) (writeb((d), (u8 __iomem *)(p) + (i)))
> +#define NV_RD08(p,i) (readb((u8 __iomem *)(p) + (i)))
> +#define NV_WR16(p,i,d) (__raw_writew((d), (u16 __iomem *)(p) + (i)/2))
> +#define NV_RD16(p,i) (__raw_readw((u16 __iomem *)(p) + (i)/2))
> +#define NV_WR32(p,i,d) (__raw_writel((d), (u32 __iomem *)(p) + (i)/4))
> +#define NV_RD32(p,i) (__raw_readl((u32 __iomem *)(p) + (i)/4))

I don't see the difference to your other patch. Did you put in the wrong
patch?

Linus
-
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