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?

And I'm pretty certain new user interfaces need to be documented.

NAK.
							Pavel

> Chen Yu (2):
>   PM / sleep: Make DPM watchdog depend on PM_SLEEP
>   PM / Sleep: Expose DPM watchdog timeout to sysfs
> 
>  drivers/base/power/main.c    |  4 +++-
>  include/linux/sched/sysctl.h |  4 ++++
>  kernel/power/Kconfig         |  2 +-
>  kernel/sysctl.c              | 16 ++++++++++++++++
>  4 files changed, 24 insertions(+), 2 deletions(-)
> 

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