Re: [PATCH 1/1] acer-wmi: switch driver to dev_pm_ops

[Dmitry Torokhov]

On Wed, Jul 29, 2009 at 10:49:46PM +0200, Rafael J. Wysocki wrote:
> On Wednesday 29 July 2009, Arnaud Faucher wrote:
> 
> > As per the pm.h documentation .thaw is called after RAM image has been
> > created, in order to restore hardware state in case RAM image failed and
> > the system cannot power off.
> 
> That's not correct (please see above).  .thaw() is called after creating the
> image in case .freeze() has changed the state of the device.  This often is not
> necessary, though, so .thaw() may be skipped in many cases.  Of course, you
> should know exactly what you're doing.
> 

Umm, but thaw() _is_ called in case of hibernate failure:

        case PM_EVENT_THAW:
        case PM_EVENT_RECOVER:
                if (ops->thaw) {
                        error = ops->thaw(dev);
                        suspend_report_result(ops->thaw, error);
                }
                break;

so I don't believe you can easily skip thaw() if you have freeze() that
stops/resets device.

-- 
Dmitry
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