Re: [PATCH] Fix /sys/device/.../power/state regression

[Eric Piel <Eric.Piel@tremplin-utc.net>]

01/27/2007 02:17 PM, Pavel Machek wrote/a écrit:
> Hi!
> 
>> In 2.6.19, support for splitting driver suspend and resume callbacks 
>> into interrupt and non-interrupt contexts was added. Unfortunately, this 
>> broke /sys/device/.../power/state support for all devices. In the long 
>> run, this should be obsoleted by power management support in the 
>> individual drivers - however, in the case of network drivers (for 
>> example), currently only three drivers implement any sort of useful 
>> run-time power management.
> 
> Well... solution seems to be 'implement useful pm for more drivers'
> not 'discourage people from doing so by re-enabling broken interface'.
> 
>> --- a/Documentation/feature-removal-schedule.txt
>> +++ b/Documentation/feature-removal-schedule.txt
>> @@ -9,7 +9,8 @@ be removed from this file.
>>  What:	/sys/devices/.../power/state
>>  	dev->power.power_state
>>  	dpm_runtime_{suspend,resume)()
>> -When:	July 2007
>> +	bus->pm_has_noirq_stage()
>> +When:	Once alternative functionality has been implemented
> 
> .../power/state never worked properly. You have been warned and it is
> going to be removed. It oopses kernels... while 'only' providing power
> savings. If you are interested in power savings, please help doing
> them right.

Hi,
I realize that I'm arriving just far too late on this thread to bring 
any meaning, so that's just for the info...

I have been using this interface for a _long_ time (before june 2005, cf 
http://marc.theaimsgroup.com/?l=linux-usb-devel&m=111869558800526&w=2) 
and for different things than power saving: I can turn off my (usb) 
optical mouse when watching a movie or going to bed.

Is there any hardware independent alternative to turn off USB devices?

See you,
Eric