Messages in this thread | | | From | Juergen Beisert <> | Subject | Geode-GX1 processor in 2.6.21 | Date | Mon, 30 Apr 2007 12:51:05 +0200 |
| |
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/
| |