lkml.org 
[lkml]   [2007]   [Apr]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectGeode-GX1 processor in 2.6.21
Date
Hi all,

I do not understand it, but setting up some chipset features (tweaks) fail on
Geode GX1.

In arch/i386/kernel/cpu/cyrix.c function geode_configure() tries to enable
the "suspend on halt power saving feature". This is the line:

setCx86(CX86_CCR2, getCx86(CX86_CCR2) | 0x88);

If this register is 0x00 before, it is still 0x00 after this line. If I change
the line into this:

ccr2 = getCx86(CX86_CCR2);
ccr2 |= 0x88;
setCx86(CX86_CCR2, ccr2);

register ccr2 is 0x88 after the setCx86 call and the power saving feature is
active (and BTW: the TSC is useless then, because it also stops when the CPU
runs into a HLT instruction).

setCx86 and getCx86 are macros defined in include/asm-i386/processor.h:

#define getCx86(reg) ({ outb((reg), 0x22); inb(0x23); })

#define setCx86(reg, data) do { \
outb((reg), 0x22); \
outb((data), 0x23); \
} while (0)

Maybe the compiler does the wrong thing if someone uses these macros in the
same instruction?

Regards
Juergen
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2007-04-30 12:53    [W:0.053 / U:0.688 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site