* [PATCH] matroxfb: fix incorrect use of memcpy_toio()
@ 2010-08-11 20:27 Ondrej Zary
2010-08-11 20:41 ` Andrew Morton
0 siblings, 1 reply; 3+ messages in thread
From: Ondrej Zary @ 2010-08-11 20:27 UTC (permalink / raw)
To: Petr Vandrovec
Cc: Andrew Morton, Jean Delvare, linux-fbdev, Kernel development list
Fix incorrect use of memcpy_toio() in matroxfb that broke in 2.6.34 on x86.
Signed-off-by: Ondrej Zary <linux@rainbow-software.org>
--- 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 2010-08-03 18:13:46.000000000 +0200
@@ -151,13 +151,13 @@ static inline void mga_writel(vaddr_t va
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:
+ * iowrite32_rep 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);
+ iowrite32_rep(va.vaddr, src, len >> 2);
#else
u_int32_t __iomem* addr = va.vaddr;
--
Ondrej Zary
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH] matroxfb: fix incorrect use of memcpy_toio()
2010-08-11 20:27 [PATCH] matroxfb: fix incorrect use of memcpy_toio() Ondrej Zary
@ 2010-08-11 20:41 ` Andrew Morton
2010-08-11 21:16 ` Ondrej Zary
0 siblings, 1 reply; 3+ messages in thread
From: Andrew Morton @ 2010-08-11 20:41 UTC (permalink / raw)
To: Ondrej Zary
Cc: Petr Vandrovec, Jean Delvare, linux-fbdev,
Kernel development list
On Wed, 11 Aug 2010 22:27:42 +0200
Ondrej Zary <linux@rainbow-software.org> wrote:
> Fix incorrect use of memcpy_toio() in matroxfb that broke in 2.6.34 on x86.
>
Thanks.
What was incorrect about it? And what is the user-visible effect of
this regression?
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] matroxfb: fix incorrect use of memcpy_toio()
2010-08-11 20:41 ` Andrew Morton
@ 2010-08-11 21:16 ` Ondrej Zary
0 siblings, 0 replies; 3+ messages in thread
From: Ondrej Zary @ 2010-08-11 21:16 UTC (permalink / raw)
To: Andrew Morton
Cc: Petr Vandrovec, Jean Delvare, linux-fbdev,
Kernel development list
On Wednesday 11 August 2010 22:41:36 Andrew Morton wrote:
> On Wed, 11 Aug 2010 22:27:42 +0200
>
> Ondrej Zary <linux@rainbow-software.org> wrote:
> > Fix incorrect use of memcpy_toio() in matroxfb that broke in 2.6.34 on
> > x86.
>
> Thanks.
>
> What was incorrect about it? And what is the user-visible effect of
> this regression?
Screen is completely corrupted since 2.6.34. Bisection revealed that it's
caused by commit 6175ddf06b6172046a329e3abfd9c901a43efd2e. H. Peter Anvin
explained that memcpy_toio() does not copy data in 32bit chunks anymore on
x86.
See: http://lkml.org/lkml/2010/8/2/409
--
Ondrej Zary
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2010-08-11 21:16 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2010-08-11 20:27 [PATCH] matroxfb: fix incorrect use of memcpy_toio() Ondrej Zary
2010-08-11 20:41 ` Andrew Morton
2010-08-11 21:16 ` Ondrej Zary
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).