On 22/01/08 12:18 +0100, Arnd Hannemann wrote: > Hi Lars, > > Lars Heete schrieb: > > Hello, > > > > On Tuesday 22 January 2008 10:03:08 am Arnd Hannemann wrote: > >> Jordan Crouse wrote: > >>> Okay - I've been exploring a little bit more. I talked to the TinyBIOS > >>> developer, and he verified that TinyBIOS shouldn't use any MFGPT timers. > >>> He also told me that the mysterious "MFGPT workaround" was in fact the > >>> magic MFGPT erasing MSR that was in the old kernel driver. > >>> > >>> So with the "MFGPT workaround" turned off, TinyBIOS should be acting like > >>> the OLPC firmware with regards to timers, yet it is not. So that is > >>> curious. I think I might have identified a race condition in the code, > >>> but I'm not 100% sure thats the same problem that the ALIX platform is > >>> seeing. > >>> > >>> Anrd and others - will you please try the attached patch on your platform > >>> with the "MFGPT workaround" turned off and mfgpts enabled, and send out > >>> the dmesg? > >> Of course, tinyBios version v0.99, "MFGPT workaround" turned off, > >> CONFIG_GEODE_MFGPT_TIMER=n: > >> > >> [ 67.369697] NET: Registered protocol family 16 > >> [ 67.383059] geode-mfgpt: IRQ MSR=0:0 > >> [ 67.394058] geode-mfgpt: NMI MSR=0:0 > >> [ 67.405049] geode-mfgpt: Unrestricted sources=0 > >> [ 67.418909] geode: 8 MFGPT timers available. > >> [ 67.433211] PCI: PCI BIOS revision 2.10 entry at 0xfcd03, last bus=0 > >> > >> same with CONFIG_GEODE_MFGPT_TIMER=y (sorry, without move printk patch): > >> > >> [ 22.289349] NET: Registered protocol family 16 > >> [ 22.302716] geode-mfgpt: IRQ MSR=0:0 > >> [ 22.313716] geode-mfgpt: NMI MSR=0:0 > >> [ 22.324704] geode-mfgpt: Unrestricted sources=0 > >> [ 22.338566] geode-mfgpt: Registered timer 0 > >> [ 22.351393] mfgpt-timer: registering the MFGT timer as a clock event. > >> ^^^^ Hangs here > > I had the same problem with MFGPT Timers and alix (BIOS v0.99). I found > > that > > if you use a different interrupt than the default 7 for MFGPT (just append > > mfgpt_irq=8 to the kernel commandline), the timer seems to work. > > Indeed. > Strange, it works at least with mfgpt_irq=8 (rtc) and mfgpt_irq=5 (audio):
That is very unfortunate. We must continue to investigate. > [ 21.805129] geode-mfgpt: IRQ MSR=0:0 > [ 21.816129] geode-mfgpt: NMI MSR=0:0 > [ 21.827116] geode-mfgpt: Unrestricted sources=0 > [ 21.840979] geode-mfgpt: Registered timer 0 > [ 21.853806] mfgpt-timer: registering the MFGT timer as a clock event. > [ 21.873576] geode: 8 MFGPT timers available. > [ 21.887962] PCI: PCI BIOS revision 2.10 entry at 0xfcd03, last bus=0 > <snip> > I noted that "rtc" disappeared, do I have any drawback of this? > I assume that the mfgpt-timer cannot be shared? No. We figured that was the best way to go. I don't know if there are any technical reasons why it can't be shared, other then latency problems. But I would still prefer to figure out why 7 doesn't work - because there is nothing in the hardware or kernel code that should prevent that. Arnd - if you don't mind doing a little bit more debug work. You've already given us the MSRs for 0x51400020 - 0x51400023. Can you now give us 0x51400024-0x51400027, as well as 5140004E? Our current working theory is that IRQ7 (traditionally used by the LPT port) is still conflicting somewhere. Jordan -- Jordan Crouse Systems Software Development Engineer Advanced Micro Devices, Inc. -- 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/
