Re: 2.6.24-rc8 hangs at mfgpt-timer

[Arnd Hannemann <hannemann@i4.informatik.rwth-aachen.de>]

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

> 
> This will give us some debug information that I can use to ensure that
> the interrupts are set up correctly.  You can leave the timer tick disabled
> if you want.

> 
> Thanks,
> Jordan
> 

Arnd