Re: [PATCH -mm 6/7] PM: Remove power_state.event checks from suspend core code

["Rafael J. Wysocki" <rjw@sisk.pl>]

On Friday, 15 June 2007 04:00, Alan Stern wrote:
> On Fri, 15 Jun 2007, Rafael J. Wysocki wrote:
> 
> > On Thursday, 14 June 2007 16:21, David Brownell wrote:
> > > On Wednesday 13 June 2007, Rafael J. Wysocki wrote:
> > > > From: Rafael J. Wysocki <rjw@sisk.pl>
> > > > 
> > > > The suspend routines should be called for every device during a system sleep
> > > > transition, regardless of the device's state, so that drivers can regard these
> > > > method calls as notifications that the system is about to go to sleep, rather
> > > > than as directives to put their devices into the 'off' state.
> > > 
> > > Did you audit all the drivers to make sure this won't break things?
> > > Like for example through inappropriate pci_save_state() calls?
> > 
> > I did, but not very carefully.
> > 
> > > I'd really expect this patch would break things...
> > 
> > Well, in that case I'll have a closer look at them.
> 
> It might not be all that bad.  One would expect problems to occur only 
> in cases where devices were already suspended at the time of a system 
> sleep transition.  Since relatively few drivers currently implement 
> runtime PM -- and those that do are likely to be more careful about 
> not blindly making state changes -- there might not be too much 
> trouble.

Yes, in fact I've had no problems related to that so far (tested the patch on
four different machines).

Greetings,
Rafael


-- 
"Premature optimization is the root of all evil." - Donald Knuth