On Mon, 23 Jul 2007 08:50:41 -0700, H. Peter Anvin wrote: >Mikael Pettersson wrote: >> On this machine (Gigabyte mobo with i815EP chipset and a PIII), >> APM worked fine up to 2.6.22. With 2.6.23-rc1 however the APM >> driver fails to locate the APM bios: >> >> --- dmesg-2.6.22 2007-07-23 14:07:46.000000000 +0200 >> +++ dmesg-2.6.23-rc1 2007-07-23 14:48:24.000000000 +0200 >> @@ -102,7 +105,7 @@ >> Unpacking initramfs... done >> Freeing initrd memory: 976k freed >> Machine check exception polling timer started. >> -apm: BIOS version 1.2 Flags 0x07 (Driver version 1.16ac) >> +apm: BIOS not found. >> io scheduler noop registered >> io scheduler anticipatory registered (default) >> io scheduler deadline registered >> >> The only change in 2.6.23-rc1 to arch/i386/kernel/apm.c is a >> trivial nofreeze flag removal, so I suspect the boot code changes, >> perhaps the new arch/i386/boot/apm.c:query_apm_bios(). >> > >Seems like a reasonable suspicion. > >Could you try the attached patch and: > >a) see if it helps the situation, and >b) tell me what it prints? > > -hpa
Only the first printf() triggers, and it prints: apm: err = 0, ax = 0x102, bx = 0x504d, cx = 0x7 The err and bx checks will succeed, but the "if (cx & 0x02)" check will cause query_apm_bios() to return failure. I compared this check with the original assembly code, and it turns out that the i386 boot rewrite accidentally inverted the sense of this check. I've just posted a patch to fix it. /Mikael - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
