There was already a measure against wrongly identifying HP printers as media players, but it is a rather dirty workaround which does not work any more (therefore this bug). The rule in the end of 69-libmtp.rules checks the absence of the env variable libsane_matched and this variable is set for all HP printers by HPLIP. First, this rule fails miserably if HPLIP is not installed, and I cannot imagine that the libmtp package depends on HPLIP only to identify unsupported devices. Also the libmtp rules are applied for both "add" and "bind" actions, whereas the rules of HPLIP (56-hpmud.rules) are only applied for "add" and so the bug happens on a "bind" action, here the HPLIP rules do not set said env variable and so the libmtp rules probe the HP printers.
One can theoretically work around this problem by mucking with the UDEV rules of HPLIP, but this is a REALLY DIRTY workaround, so please DO NOT add an hplip task to this bug report. In addition, HPLIP will not be installed by default any more in the not too far future, as prnting and scanning will get snapped. Also we want printer driver Snaps (Printer Applications) not to run as root if possible, so we need to be sure that USB printer device files always belong to the group "lp" for all printer manufacturers and without HPLIP. -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to pulseaudio in Ubuntu. https://bugs.launchpad.net/bugs/1863239 Title: /dev/bus/usb/*/* device file of HP multi-function printer assigned to "audio" group Status in libmtp package in Ubuntu: Confirmed Status in pulseaudio package in Ubuntu: Invalid Status in systemd package in Ubuntu: Invalid Status in udev package in Ubuntu: Invalid Bug description: When testing HPLIP I found out that CUPS backends can access my printer only when they are running as root, when they are running as the special user lp, as it is usually the case, they cannot access the printer. So I tried to find out why and saw that the /dev/bus/usb/*/* device file for the printer has group ownership "audio" and not "lp": till@till-x1yoga:~/ubuntu/hplip/focal/debian/hplip-3.19.12+dfsg0$ ll /dev/bus/usb/*/* crw-rw-r-- 1 root root 189, 0 Feb 11 14:17 /dev/bus/usb/001/001 crw-rw-r-- 1 root root 189, 2 Feb 11 14:17 /dev/bus/usb/001/003 crw-rw-r-- 1 root root 189, 3 Feb 11 14:17 /dev/bus/usb/001/004 crw-rw-r-- 1 root plugdev 189, 4 Feb 14 12:23 /dev/bus/usb/001/005 crw-rw-r-- 1 root root 189, 5 Feb 11 14:17 /dev/bus/usb/001/006 crw-rw----+ 1 root audio 189, 62 Feb 14 12:37 /dev/bus/usb/001/063 crw-rw-r-- 1 root root 189, 128 Feb 11 14:17 /dev/bus/usb/002/001 crw-rw-r-- 1 root root 189, 130 Feb 13 09:38 /dev/bus/usb/002/003 till@till-x1yoga:~/ubuntu/hplip/focal/debian/hplip-3.19.12+dfsg0$ The printer is the device /dev/bus/usb/001/063: till@till-x1yoga:~/ubuntu/hplip/focal/debian/hplip-3.19.12+dfsg0$ lsusb Bus 002 Device 003: ID 0b95:1790 ASIX Electronics Corp. AX88179 Gigabit Ethernet Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub Bus 001 Device 005: ID 138a:0097 Validity Sensors, Inc. Bus 001 Device 004: ID 04f2:b5ce Chicony Electronics Co., Ltd Integrated Camera Bus 001 Device 003: ID 8087:0a2b Intel Corp. Bus 001 Device 006: ID 056a:50b7 Wacom Co., Ltd Pen and multitouch sensor Bus 001 Device 063: ID 03f0:7a12 HP, Inc HP OfficeJet Pro 8730 Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub till@till-x1yoga:~/ubuntu/hplip/focal/debian/hplip-3.19.12+dfsg0$ There must be a bug somewhere in the UDEV rules. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/libmtp/+bug/1863239/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
