Subject: Re: pci_set_power_state() failure and breaking suspend

From: Scott Wood <[email-masked]>
Date: Tue, 24 Oct 2006 11:09:16 -0500

Rafael J. Wysocki wrote:
> On Tuesday, 24 October 2006 08:54, Benjamin Herrenschmidt wrote:
>>However, this raises the question of do we actually want to prevent
>>machines to suspend when they have a PCI device that don't have the PCI
>>PM capability ? I'm asking that because I can easily imagine that sort
>>of construct growing into more drivers (sounds logical if you don't
>>think) and I can even imagine somebody thinking it's a good idea to slap
>>a __must_check on pci_set_power_state() ... 
> 
> 
> As far as the suspend to RAM is concerned, I don't know.
> 
> For the suspend to disk we can ignore the error if we know that the device
> in question won't do anything like a DMA transfer into memory while we're
> creating the suspend image.

I think it should be ignored for suspend-to-RAM as well; even if a 
device or two is consuming unnecessary power, it's better than not being 
able to suspend at all, causing more things to consume unnecessary power.

At most, a warning should be issued so the user knows what's going on, 
and can choose whether to suspend to disk instead (or choose to complain 
to the device manufacturer).

-Scott