|Summary:||usb_suspend and scanner canoscan n670u|
|Product:||Drivers||Reporter:||Elmar Neugebuer (elmar_n)|
|Component:||USB||Assignee:||Alan Stern (stern)|
|Kernel Version:||2.6.20, 2.6.21-git~||Tree:||Mainline|
|Bug Depends on:|
Description Elmar Neugebuer 2007-05-06 02:47:30 UTC
Most recent kernel where this bug did *NOT* occur: Distribution: ubuntu 7.04 Hardware Environment: scanner canoscan n670u Software Environment: Problem Description: Is a usual problem with scanner and usb_suspend. The differenc is after scanner is attached it is not working if i disable autosuspend ( echo -1 > /sys/module/usbcore/parameters/autosuspend ) it's not working too. But if i plug out scanner, disable autosupend, plugin and enable autosupend agene ewerything working. May be there is nothing bother about and just blacklist my scanner for usb_suspend.
Comment 1 Elmar Neugebuer 2007-05-06 02:48:26 UTC
Created attachment 11403 [details] dmesg1 here is dmesg after boot and with enabled autosuspend
Comment 2 Elmar Neugebuer 2007-05-06 02:50:09 UTC
Created attachment 11404 [details] lsusb here is verbose lsusb. but if you like shor way take just this: Bus 001 Device 008: ID 04a9:220d Canon, Inc. CanoScan N670U/N676U/LiDE 20
Comment 3 Alan Stern 2007-05-06 15:18:59 UTC
From the dmesg1 log, it looks like you set the autosuspend delay to 0. That's not a good idea; it generates lots of unnecessary suspends and resumes. Try leaving it at the default value of 2. By the way, you should realize that echo -1 > /sys/module/usbcore/parameters/autosuspend doesn't really disable autosuspend. Rather, it causes autosuspend to be disabled for new devices as they are plugged in -- but it doesn't affect the setting for devices that are already attached. To disable autosuspend for a particular device you should do: echo -1 >/sys/bus/usb/devices/XXX/power/autosuspend where XXX is the sysfs pathname of your device (in this case 1-2). It would be interesting to see if the scanner really does need to be blacklisted for suspend. You can test that: write -1 to the usbcore parameter, then plug in the scanner, then set the scanner's autosuspend delay to 2 and wait for it to be suspended. Then see if it still works.
Comment 4 Natalie Protasevich 2007-06-14 10:55:25 UTC
Elmar, did you have chance to try recommendations in #3? Thanks!
Comment 5 Rafael J. Wysocki 2007-08-08 10:14:15 UTC
Well, I think we have not received sufficient information from the reporter.
Comment 6 Alan Stern 2007-08-08 12:31:56 UTC
We have found that many, many scanners don't like to be suspended. The current development kernel has a blacklist entry for this scanner. In the end we may blacklist the entire class. Elmar, do you have anything new to report? Otherwise this bug report will be closed in a few days.
Comment 7 Rafael J. Wysocki 2007-09-12 10:06:03 UTC
(In reply to comment #6) > Elmar, do you have anything new to report? Otherwise this bug report will be > closed in a few days. Can you close it, please?
Comment 8 Alan Stern 2007-09-12 11:18:57 UTC
The scanner in question has been added to the quirks list. Closing the bug report.