On Wed, 31 Jan 2007, Oliver Neukum wrote: > Hi, > > this preliminary patch should suspend your mouse, if it supports remote > wakeup. In fact it should do this to all devices which are HID, claimed by > the input layer and support remote wakeup. > > It works for me with my mouse. I've tested letting it autosuspend and > resume. It survives going to a text console, init 3 and hotplugging. > Anything else is untested. I think it'll crash and burn with PID devices. > I am working on that. > > I am pretty sure that it actually goes to sleep taking the root hub with it. > I'd be interested in knowing how much power it really saves. Short of > running dry my laptop's battery I have no way of telling. > > You need to compile with EXPERIMENTAL & USB_SUSPEND. > > Regards > Oliver
This looks more complicated than it should be. In particular, the addition of a new "idle" timer should not be needed. We already have an autosuspend timer: the one embedded in the autosuspend delayed_work struct inside struct usb_device. What you really want to do is make the delay configurable per-device instead of relying on a fixed constant USB_AUTOSUSPEND_DELAY. Doing things that way would remove a tremendous amount of complexity from your patch. In fact, I have already been considering making USB_AUTOSUSPEND_DELAY and module parameter for usbcore. The idea is this: Some device must not be autosuspended. Maybe the device can't handle it, maybe its upstream hub doesn't work right,... There's even the case of a broken BIOS which unilaterally restarts a suspended EHCI controller! Anyway, userspace has to be able to tell the kernel not to suspend these devices, _before_ the default autosuspend has already kicked in. At boot-up time this can't be done; userspace is too busy with start-up tasks and other initializations and 2 seconds is just not enough time. If the user could put usbcore.autosuspend_delay=60 on the boot command line, then it would be possible to prevent some devices from being autosuspended. Alan Stern P.S.: Nowadays we're supposed to use DEFINE_SPINLOCK(). ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
