Messages in this thread Patch in this message | | | From | Ondrej Zary <> | Subject | Re: 6175ddf06b6172046a329e3abfd9c901a43efd2e breaks matroxfb console | Date | Mon, 2 Aug 2010 23:35:10 +0200 |
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On Monday 02 August 2010 23:15:33 H. Peter Anvin wrote: > On 08/02/2010 02:14 PM, Ondrej Zary wrote: > > On Monday 02 August 2010 23:04:28 H. Peter Anvin wrote: > >> On 08/02/2010 12:49 PM, Ondrej Zary wrote: > >>> Hello, > >>> matroxfb (at least with Mystique and Mystique 220) stopped working in > >>> 2.6.34 - the screen is completely corrupted. Bisection shows that > >>> 6175ddf06b6172046a329e3abfd9c901a43efd2e is first bad commit. > >>> > >>> Reverting 6175ddf06b6172046a329e3abfd9c901a43efd2e in 2.6.34 fixes the > >>> problem (1c5b9069e12e20d2fe883076ae0bf73966492108 must be reverted > >>> first). > >> > >> Sounds like another driver which used memcpy_toio() when it should have > >> used iowrite32_rep() or __iowrite32_copy(). > >> > >> Hmm... is __iowrite32_copy() and iowrite32_rep() redundant? If so, we > >> should get rid of the former. > > > > There is a wrapper in drivers/video/matrox/matroxfb_base.h (see below) > > with some comment. So this commit changed one of the three points? > > > > static inline void mga_memcpy_toio(vaddr_t va, const void* src, int len) > > { #if defined(__alpha__) || defined(__i386__) || defined(__x86_64__) /* > > * memcpy_toio works for us if: > > * (1) Copies data as 32bit quantities, not byte after byte, > > * (2) Performs LE ordered stores, and > > * (3) It copes with unaligned source (destination is guaranteed > > to be page * aligned and length is guaranteed to be multiple of 4). > > */ > > memcpy_toio(va.vaddr, src, len); > > #else > > Yes, point (1) is not guaranteed by memcpy_toio().
Now I wonder how many drivers will this break...
The patch below fixes it for me. Is it correct on all architectures?
--- linux-2.6.35-rc2/drivers/video/matrox/matroxfb_base.h 2010-06-06 05:43:24.000000000 +0200 +++ linux-2.6.35-rc3/drivers/video/matrox/matroxfb_base.h 2010-08-02 23:31:34.000000000 +0200 @@ -157,7 +157,7 @@ static inline void mga_memcpy_toio(vaddr * (3) It copes with unaligned source (destination is guaranteed to be page * aligned and length is guaranteed to be multiple of 4). */ - memcpy_toio(va.vaddr, src, len); + iowrite32_rep(va.vaddr, src, len); #else u_int32_t __iomem* addr = va.vaddr;
-- Ondrej Zary
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