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    SubjectRe: [GEODE] Geode GX/LX watchdog timer (was 2.6.24-rc8 hangs at mfgpt-timer)

    Jordan Crouse wrote:
    > On 17/01/08 23:52 +0100, Arnd Hannemann wrote:
    >>>> Watchdog for the new API would be great :-)
    >>> Coming soon.
    > As promised, a watchdog driver for the Geode GX/LX processors is attached.
    > I basically just ported the previous patch forward to 2.6.24.

    Great work!

    > I also have good news or bad news depending on your perspective. I wanted
    > to test this against 2.6.24, and OLPC is stuck at an older kernel version,
    > so I had to test this with coreboot (LinuxBIOS) on another Geode
    > platform. Like all BIOSen execpt for the OLPC firmware, coreboot uses
    > VSA (SMM handler) which consumes all the timers.
    > So I used the magical MSR and surprise! - the timer tick hung.
    > I compiled out the timer tick, and tested the watchdog timer instead,
    > and it worked fine on timer 0. So I don't think the MFGPTs themselves
    > have anything to do with this problem, but I do think it might be
    > related to VSA and possibly interrupts too. I'm going to invoke the
    > strong BIOS fu of our LinuxBIOS / BIOS expert Marc Jones, and see what
    > he comes up with.
    > I don't know how much of a hassle it would be for Andres to get a 2.6.24
    > kernel running on the OLPC to make sure that this isn't a regression
    > in the timer tick code (I suspect it isn't a regression, but you never
    > know). I also think that it would probably be in our best interest to
    > default CONFIG_GEODE_MFGPT_TIMER to 'n' until we get this figured
    > out. Since most BIOSen don't have timers available, that shouldn't affect
    > too many people.
    > So, anyway, enjoy the watchdog timer - I hope it meets everybody's
    > expectations for the 2.6.25 kernel.

    Thanks a lot for this, it works great! (with CONFIG_GEODE_MFGPT_TIMER
    not set).
    However some minor issues:
    Could the name of the /dev entry perhaps be changed from
    "geode-watchdog" to "watchdog" instead?
    I think all other watchdogs use "watchdog", and using two different
    watchdogs in the same machine won't work anyway, because of the same
    minor number, right?

    As a second point my gcc (4.1.2) issues a warning:

    drivers/watchdog/geodewdt.c: In function ‘geodewdt_remove’:
    drivers/watchdog/geodewdt.c:256: warning: control reaches end of
    non-void function

    which I think is a valid one.

    > Jordan
    Best regards,
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