Re: [PATCH 0/2][RFC] PM / sleep: Expose DPM watchdog timeout to sysfs

[Pavel Machek <pavel@ucw.cz>]

Hi!

> > > Recently we have a new report that, the harddisk can not
> > > resume on time due to firmware issues, and got a kernel
> > > panic because of DPM watchdog timeout. Since the default
> > > timeout has once been modified from 12 to 60 seconds, we
> > > might still encounter new case which requires a longer timeout,
> > > so expose the value to sysfs and let the users decide which
> > > value is appropriate, meanwhile this can also ease the debugging
> > > process.
> > > 
> > > The first patch is to force DPM watchdog depending on CONFIG_PM_SLEEP,
> > > thus the second patch which does the actual work, can use
> > > CONFIG_DPM_WATCHDOG safely without checking CONFIG_PM_SLEEP.
> > 
> > Kernel should just work. User should not have to configure random
> > knobs to have working suspend/hibernation.
> > 
> > We do not want "CONFIG_BREAK_SUSPEND" so I believe we don't want
> > "CONFIG_DPM_WATCHDOG". If normal users select it and it breaks their
> > system, make it depend on "CONFIG_EXPERT" or hide it in some other
> > way or maybe remove it from Kconfig altogether. 
> >
> > Or maybe CONFIG_DPM_WATCHDOG should contain numeric value that user
> > has to select?
> > 
> Yes, if people select it then they have the risk to break their system,
> and the original thought of the patch is to behave like a diagnosis to
> make it easier for the users to figure it out, how much time it takes
> to suspend/resume a bogus peripheral, without recomping the kernel.
> -- currently the timeout value for CONFIG_DPM_WATCHDOG can be adjusted
> by menuconfig, but bug reporter might have to recompile the kernel
> to confirm, and it takes some time to get a feedback from them, so...

Please don't add sysfs knobs for this. People should not need to
adjust sysfs files to get working kernel.

You can for example make the default 120 seconds.
									Pavel
-- 
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