Public bug reported: After the upgrade to Kubuntu 10.10 I was not able connect to my buspirate (FTDI USB -> serial). Minicom reported: minicom: cannot open /dev/buspirate: Device or resource busy
uname -a : Linux lorelei 2.6.35-22-generic #34-Ubuntu SMP Sun Oct 10 09:26:05 UTC 2010 x86_64 GNU/Linux This was working fine before the upgrade. At that time I had the following udev rule: 98-buspirate.rules UBSYSTEM=="tty", ATTRS{serial}=="A7004DMs", GROUP="users", MODE="0660", SYMLINK+="buspirate" I thought it could have something to do with the rule so I removed it and reloaded the udev rules: sudo udevadm control --reload-rules Then again I could acces /dev/ttyUSB0 as normal user. Today after a reboot I wanted to access my buspirate through minicom (udev rule removed) and could not access /dev/ttyUSB0: minicom: cannot open /dev/ttyUSB0: Device or resource busy I checked the permissions: p...@lorelei:~$ ls -al /dev/ttyUSB0 crw-rw---- 1 root dialout 188, 0 2010-10-18 20:52 /dev/ttyUSB0 Group membership: p...@lorelei:~$ groups ping adm dialout cdrom plugdev users lpadmin admin sambashare vboxusers Even added myself to the uucp group but to nothing changed. Tried reloading the ftdi_sio kernel module but didn't help. dmesg entries look normal I think: [ 7795.737299] ftdi_sio ttyUSB0: FTDI USB Serial Device converter now disconnected from ttyUSB0 [ 7795.737309] ftdi_sio 6-2:1.0: device disconnected [ 7798.963590] usb 6-2: new full speed USB device using uhci_hcd and address 8 [ 7799.178150] ftdi_sio 6-2:1.0: FTDI USB Serial Device converter detected [ 7799.178188] usb 6-2: Detected FT232RL [ 7799.178192] usb 6-2: Number of endpoints 2 [ 7799.178196] usb 6-2: Endpoint 1 MaxPacketSize 64 [ 7799.178199] usb 6-2: Endpoint 2 MaxPacketSize 64 [ 7799.178203] usb 6-2: Setting MaxPacketSize 64 [ 7799.179162] usb 6-2: FTDI USB Serial Device converter now attached to ttyUSB0 I did an strace of minicom to see if I got any wiser: .... stat("/var/lock", {st_mode=S_IFDIR|S_ISVTX|0777, st_size=40, ...}) = 0 open("/var/lock/LCK..ttyUSB0", O_RDONLY) = -1 ENOENT (No such file or directory) umask(022) = 022 open("/var/lock/LCK..ttyUSB0", O_WRONLY|O_CREAT|O_EXCL, 0666) = 3 getpid() = 10590 write(3, " 10590\n", 11) = 11 close(3) = 0 umask(022) = 022 rt_sigaction(SIGALRM, {0x4199f0, [ALRM], SA_RESTORER|SA_RESTART, 0x7f42a5850c20}, {SIG_DFL, [], 0}, 8) = 0 alarm(4) = 0 open("/dev/ttyUSB0", O_RDWR|O_NOCTTY|O_NONBLOCK) = -1 EBUSY (Device or resource busy) alarm(0) = 4 rt_sigaction(SIGALRM, {SIG_IGN, [ALRM], SA_RESTORER|SA_RESTART, 0x7f42a5850c20}, {0x4199f0, [ALRM], SA_RESTORER|SA_RESTART, 0x7f42a5850c20}, 8) = 0 .... Permissions of /var/lock can't be the cause... Using sudo I can access the buspirate, but I want to run my programs as a regular user... I did notice that connecting through minicom to /dev/ttyS0 with the same permissions is successful. ** Affects: ubuntu Importance: Undecided Status: New -- ftdi usb serial node only accessible by root https://bugs.launchpad.net/bugs/662881 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs