On Sat, 5 Feb 2011, Andrew Lutomirski wrote: > I have a Logitech MX Revolution (a cordless mouse receiver) plugged > into a Logitech G15 (a keyboard w/ a hub) plugged into an Intel Cougar > Point EHCI controller. (Results are the same on an xHCI controller, > though.) > > With autosuspend *or* runtime PM off, everything works. (Well, the > G15 is buggy and occasionally crashes and doesn't recover until > powercycled, but that even happens on Windows.) With runtime PM > enabled on the whole tree, I have problems with autosuspend. > > If I enable autosuspend on just the mouse by doing: > > echo 2 >./1-1/1-1.2/1-1.2.3/power/autosuspend > (where that device is Bus 001 Device 005: ID 046d:c51a Logitech, Inc. > MX Revolution/G7 Cordless Mouse), then after about two seconds of not > moving the mouse, the mouse ignores the first second or so of motion > when I start moving it again. > > If I enable autosuspend on just part of the keyboard by doing: > > echo 2 >./1-1/1-1.2/1-1.2.1/power/autosuspend > (that's Bus 001 Device 004: ID 046d:c221 Logitech, Inc. G11/G15 > Keyboard / Keyboard) > > then after a couple seconds of not typing, my next keystroke is lost or delayed. > > It seems to be enough to turn off runtime PM (via power/control) OR > turn off autosuspend on the keyboard device to make the keyboard work > and on the mouse device to make the mouse work. > > Is this a case of "don't do that, you fool," or is there a legitimate > bug to be fixed in the runtime pm code? > > My motherboard is Intel DH67GD (ordered just before they canceled > production) with latest BIOS. I don't think there is any bug in the code. The problem lies in the devices; they appear to be designed so as to lose some input events when waking up from suspend. This is very common among keyboard and mouse devices -- probably because autoresume was not used under Windows and hence didn't get tested. Hence my advice is, as you guessed, "Don't do that". Alan Stern -- 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
