Re: [PATCH] acerhdf: convert to dev_pm_ops

From: Peter Feuerer
Date: Tue Jul 28 2009 - 09:27:45 EST


Hi,

Borislav Petkov writes:

Hi,

On Tue, Jul 28, 2009 at 9:25 AM, Peter Feuerer<peter@xxxxxxxx> wrote:

[..]

Hmm, looking at the driver I think the only function that actually
is needed is poweroff() that would turn the fan in automatic mode
before shutting down. The driver does not perform any actions when
resuming so why bother?

Agreed.

Also, the fan comes out of warm and cold reboot in mode AUTO and
when the driver is enabled, the fan is turned off on the next run of
thermal_zone_device_update() when the read out temperature is within
limits.

Correct me if I'm wrong, but the only reason I see for setting the
fan to mode AUTO before suspending/hibernating/etc is if it is taking
a really long time to hibernate and write RAM image to disk and the
machine is getting hot during that process. Otherwise, we might just
as well do _nothing_ when suspending and remove all suspend/resume
functionality altogether, no?

This is right, currently the only reason for calling the suspend /
hibernate functions is to set the fan to auto to ensure it doesn't get
too hot while the kernel prepares the machine to suspend / hibernate.

I would like to keep the resume function too. It's a nice to see
what's happening with verbose=1.

That's not a reason for keeping code in the kernel and raising bloat
levels unnecessarily. If the driver doesn't need to do anything on
resume, then no function is needed.

I don't think the verbose message is useless. If an user has a problem with suspend / hibernate I can just ask him to load the module with verbose=1 and dmesg tells whether the module is waking up or not. Searching for such an error is much easier this way as the user doesn't have to recompile the kernelmodule. In my opinion keeping these 4 lines of code is worth it.

kind regards,
--peter
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