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
--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
