[PATCH] Watchdog: OMAP: Fix the runtime pm code to avoid module getting stuck intransition state.

Zumeng Chen zumeng.chen at windriver.com
Sun Jul 8 21:16:34 EDT 2012

于 2012年07月08日 17:26, Wim Van Sebroeck 写道:
> Hi All,
>> Hello, Lokesh,
>> One question: Does "echo 1>  /dev/watchdog" work well?
>> Regards,
>> Zumeng
> Please note hat "echo 1>  /dev/watchdog" for drivers that have the WDIOF_MAGICCLOSE
> flag set, reboots the system. This is because it opens the watchdog device ; then
> writes the characters "1" to it and then closes the watchdog. So the watchdog keeps
> running (because it didn't see the magic char "V" written to it).
Yes, this is _absolutely_ right.
> In this case (omap_wdt) it opens the watchdog device (and starts the watchdog) then
> it writes a "1" to the watchdog (so basically the watchdog is being pinged) and then
> closes the watchdog device (which stops the watchdog if NOWAYOUT was not set).

Agreed for all above, sorry for jumping in:

I just have a little question about this patch:

we have enable pm_runtime_enable(wdev->dev) in probe,
and do ret = misc_register(&(wdev->omap_wdt_miscdev));

Then this patch wants to remove pm_runtime_get_sync
in file operation function, is that right?


> Kind regards,
> Wim.

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