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SubjectRe: fix typo in geode_configre()@cyrix.c
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On Tue, Jan 09, 2007 at 06:41:56PM +0900, takada wrote:
> In kernel 2.6, write back wrong register when configure Geode processor.
> Instead of storing to CCR4, it stores to CCR3.
>
> --- linux-2.6.19/arch/i386/kernel/cpu/cyrix.c.orig 2007-01-09 16:45:21.000000000 +0900
> +++ linux-2.6.19/arch/i386/kernel/cpu/cyrix.c 2007-01-09 17:10:13.000000000 +0900
> @@ -173,7 +173,7 @@ static void __cpuinit geode_configure(vo
> ccr4 = getCx86(CX86_CCR4);
> ccr4 |= 0x38; /* FPU fast, DTE cache, Mem bypass */
>
> - setCx86(CX86_CCR3, ccr3);
> + setCx86(CX86_CCR4, ccr4);
>
> set_cx86_memwb();
> set_cx86_reorder();

Any idea what the consequence of this would be? Any chance that while
fixing this file anyhow, adding a missing variant could be done?

The patch I currently run with is this (To cyrix.c):
@@ -257,6 +257,8 @@
break;

case 4: /* MediaGX/GXm or Geode GXM/GXLV/GX1 */
+ case 11: /* SC1200 seems to return 11 or something but it is a geode gx1 too as far as I know */
+ dir0_msn = 4;
#ifdef CONFIG_PCI
/* It isn't really a PCI quirk directly, but the cure is the
same. The MediaGX has deep magic SMM stuff that handles the

After the patch I get this:

# cat /proc/cpuinfo
processor : 0
vendor_id : CyrixInstead
cpu family : 5
model : 9
model name : Geode(TM) Integrated Processor by National Semi
stepping : 1
cpu MHz : 266.759
cache size : 16 KB
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 2
wp : yes
flags : fpu tsc msr cx8 cmov mmx cxmmx
bogomips : 535.09

Before that the cpu type was unknown, the cache size wasn't there,
and a number of fixups were not being applied as far as I could tell.

I know I have had to fix the jsm serial driver which uses memcpy_toio,
and I got characters out of order on transmit on the geode, while on a
pentium 4 or athlon it works perfectly fine with the same card and driver.

My workaround (which of course isn't good for efficiency) has been:
- memcpy_toio(&ch->ch_neo_uart->txrxburst, ch->ch_wqueue + tail, s);
+ for(i=0;i<s;i++) {
+ memcpy_toio(&(ch->ch_neo_uart->txrxburst[i]), ch->ch_wqueue + tail + i, 1);
+ }
+ /*memcpy_toio(&ch->ch_neo_uart->txrxburst, ch->ch_wqueue + tail, s);*/

Could the wrong register being saved have anything to do with that?

Without my fix a burst transfer of the data 0123456789ABCDEF results in
the other end receiving: 123056749AB8DEFC

--
Len Sorensen
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