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    SubjectRe: Geode GX/LX watchdog timer (RESEND)
    Jordan Crouse schrieb:
    > On 20/01/08 14:22 +0100, Arnd Hannemann wrote:
    >> Hi,
    >> 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.
    > Resending with Arnd's concern's addressed. Thanks.

    I can confirm that it is still working fine :-)

    > Jordan
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