Re: autosuspend for HID devices, take #4
Alan Stern <[email protected]>
| Newsgroups | gmane.linux.usb.devel |
|---|---|
| Message-ID | <[email protected]> |
On Mon, 25 Jun 2007, Oliver Neukum wrote: > Am Montag, 25. Juni 2007 schrieb Jiri Kosina: > > On Fri, 22 Jun 2007, Oliver Neukum wrote: > > > > > could you please run two tests? > > > 1. set the autosuspend timeout to 0 (this'll kill usb mice) > > > > And it kills also my testing keyboard on the UHCI system. After the > > keyboard gets suspended and I hit a key, it wakes up (the LEDs come up), > > but no keypressess are produced and the keyboard gets suspended again. > > I had a hunch that UHCI handles remote wakeup incorrectly while the > hub above the device is still active. This seems to kill that theory. Setting the timeout to 0 would cause lots of weird things to happen. The driver might not even have time to query the device before it gets suspended again! > > > 2. use a 1.1 hub > > > > I grabbed a random HUB (usbhub4c from Linksys) and this made it work > > nicely even on UHCI-based system I am testing on. > > > > I will do some more debugging to check what exactly goes wrong, but I am > > leaving for OLS tomorrow. > > Is it a 1.1 hub or a 2.0 hub? If the latter you just switch the device > to ehci. Did you unload ehci_hcd for the test? > > > BTW I don't know if you recall - I reported previously that the keypresses > > are lost only if I try to hit the key very soon after the keyboard gets > > suspended. If I wait for 2 seconds (looks like exact value), then no > > keypressess are lost and the keyboard wakes up properly. > > Alan, is there something in UHCI that uses that 2 second value? No. > That indicates that something's wrong in uhci's root hub code. Could well be. I'll try duplicating the experiment: suspend the keyboard and less than 2 seconds later type some keys. I don't have the HID-autosuspend patch installed, but a manual suspend with remote wakeup should work pretty much the same. Jiri, I'll look for you at OLS. Alan Stern ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ [email protected] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel