Re: [PATCH] eeepc-laptop: enable camera by default

[Alan Jenkins]

Alan Jenkins wrote:
> Pekka Enberg wrote:
> > Hi Alan,
> >
> > On Fri, 2009-06-05 at 15:38 +0100, Alan Jenkins wrote:
> >  
> > > Ok.  I didn't bother shutting down my system, but I get a similar
> > > difference; 16 wakeups/s disabled v.s. 25 enabled.  Anecdotally,
> > > disabling the camera does help battery life, and presumably Asus had
> > > good reason to implement it!  (The shipped OS "fixes" the usability
> > > problem by patching the camera apps).
> > >
> > > BUT I found that autosuspend didn't seem to break anything, and
> > > enabling it also got me down to 16 wakeups/s.  I think this is ideal
> > > because autosuspend is automatic so I can save power without manual
> > > toggling.
> > >
> > > Here's some magic to enable autosuspend:
> > >
> > > # echo -n auto > /sys/bus/usb/drivers/uvcvideo/*:*/../power/level
> > >
> > > Ideally this wants to be enabled automatically using a udev rule.
> > >     
> >
> > Can the kernel do this by default for this specific driver on eeepc?
> >
> >             Pekka
> >
> >   
>
> Auto-suspend white-listing would be done on the basis of USB ids 
> (vendor, product).  At the moment it's expected that userspace should 
> take ownership of it.  There's no infrastructure for in-kernel 
> whitelisting.  I think.
>
> Large lists in udev rules can work, there are already lists of USB 
> devices to set permissions for libusb access, e.g. for libmtp.
>
> [CC usb list - in the hope someone will point out if I got this wrong 
> :-)]
>
> Alan

Btw I've now tested the udev rule, you can just dump this in a new 
.rules file under /etc/udev/rules.d:

SUBSYSTEM=="usb", ATTR{idVendor}=="eb1a", ATTR{idProduct}=="2761", ATTR{power/level}="auto"


Not sure who I should submit it to though :-).  debian-eeepc would take 
it, but perhaps it should go in udev's default rules.

Regards
Alan
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