On Tue, 4 Aug 2020 08:04:36 +0000 Eduardo Casais <[email protected]>
wrote:Dear Debian maintainers,
I suggest you proceed as follows with the bug report:
1. include the text below as a new section in the manpage usb-sane(5);
2. mark the bug report as solved.
Sincerely,
Eduardo Casais
BEGIN TEXT FOR SANE-USB(5)
AUTOSUSPEND
Some USB scanners (e.g. Canon LiDE 30) may not function properly, with
the following typical symptoms:
a) The front-end scanning program, such as xsane or simplescan, spends a
long time trying to contact the scanner, but fails to establish a
connection.
b) After a successful scan, connection with the scanner is lost, as if
the device had been suddenly unplugged from the computer.
c) Scanning apparently works, with the front-end program displaying
progress status and announcing successful completion, but nothing
actually happens: the scanner remains completely inactive and only
entirely black pages are returned.
The source of these difficulties is the USB AUTOSUSPEND mode, which
causes the scanner to enter a state from which it can be awakened
neither by the front-end program, nor by the back-end libsane library.
The problem is solved by instructing the power management of the
computer to disable USB AUTOSUSPEND for the device in question.
1. In a terminal window, type the lsusb command to identify the scanner
among all other USB devices; for instance:
... other USB devices ...
Bus 001 Device 004: ID 04a9:220e Canon, Inc. CanoScan N1240U/LiDE 30
... other USB devices ...
2. Edit, with superuser privileges, the file /etc/default/tlp, find the
line containing the attribute USB_BLACKLIST, uncomment it if necessary,
and add the device id to the parameter list thus:
USB_BLACKLIST="04a9:220e"
Several device ids can be listed, separated by spaces.
The modification takes effect at the next system restart.
END TEXT FOR SANE-USB(5)
