On Thu, Aug 17, 2017@01:06:32PM -0400, Martin K. Petersen wrote:

Keith,

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My only concern is if this value extends past the DPM_WATCHDOG
timeout value. If it does we're going to end up panic()ing the
kernel during suspends. If others agree I think we should set it to
the minimum value of DPM_WATCHDOG_TIMEOUT and shutdown_timeout.

I don't have a problem with that. Keith?

Sounds good to me as well.

Hrm, this gets pretty messy.

DPM_WATCHDOG_TIMEOUT is buried deep in the config options (hidden behind
PM_DEBUG and EXPERT). And as a result doesn't appear to be enabled in
most common kernel configs. It also isn't exported from the PM subsystem
in a generic way.

In addition, I'm not sure what we'd do in case a device demands a 10
second shutdown time but the user has the kernel configured with a 2
second DPM watchdog. Then what? The device is still going to take 10
seconds to complete the shutdown request.

ugh, I thought it would be as easy as if (IS_ENABLED(CONFIG_DPM_WATCHDOG))
but I guess since that's a runtime check GCC cant remove the scope below,
since it's not known at compilation time.

We wont be able to fix this without some gross ifdefs/ifndefs.

I guess we can do a dev_warn() or something if the shutdown time is >
than some threshold instead? That way if people are getting sporatic
panics on suspends we can see that warning and fix it from there?