Re: Changes to sysfs PM layer break userspace

[Arjan van de Ven]

On Tue, 2006-12-19 at 20:08 +0000, Matthew Garrett wrote:
> On Tue, Dec 19, 2006 at 09:03:21PM +0100, Arjan van de Ven wrote:
> 
> > humm shouldn't the driver do this when the interface is brought down?
> > sounds like you're playing with fire to do this behind the drivers'
> > back....
> 
> I'm not sure. Suspending the chip means you lose things like link beat 
> detection, so it's not something you necessarily want to automatically 
> tie to something like interface status. 

right now the "spec" for Linux network drivers assumes that you put the
NIC into D3 on down, except for cases where Wake-on-Lan is enabled etc.

> Some chips support more 
> fine-grained power management, so we could do something more sensible in 
> that case - but right now, there doesn't seem to be a lot of driver 
> support for it.

sounds like that's the right approach at least .. not talking to the PCI
hardware directly from userspace...

I can see the point of having more than just "UP" and "DOWN" as
interface states; "UP", "DOWN" and "OFF" for example... 


-- 
if you want to mail me at work (you don't), use arjan (at) linux.intel.com
Test the interaction between Linux and your BIOS via http://www.linuxfirmwarekit.org

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