$ sudo uname -a Linux iugo 3.7.0-4-generic #12~lp1085115v1 SMP Fri Nov 30 20:57:19 UTC 2012 i686 i686 i686 GNU/Linux (i have this kernel because of Bug #1085115, but the standard ubuntu kernel behaves exactly similar)
$ sudo dmesg|grep tty [ 0.000000] console [tty0] enabled [ 0.663436] 00:06: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A [ 0.683785] 00:07: ttyS1 at I/O 0x2f8 (irq = 3) is a 16550A $ sudo ls -al /dev/ttyS? crw-rw---- 1 root dialout 4, 64 Dec 8 10:05 /dev/ttyS0 crw-rw---- 1 root dialout 4, 65 Dec 8 10:05 /dev/ttyS1 crw-rw---- 1 root dialout 4, 66 Dec 8 10:05 /dev/ttyS2 crw-rw---- 1 root dialout 4, 67 Dec 8 10:05 /dev/ttyS3 crw-rw---- 1 root dialout 4, 68 Dec 8 10:05 /dev/ttyS4 crw-rw---- 1 root dialout 4, 69 Dec 8 10:05 /dev/ttyS5 crw-rw---- 1 root dialout 4, 70 Dec 8 10:05 /dev/ttyS6 crw-rw---- 1 root dialout 4, 71 Dec 8 10:05 /dev/ttyS7 crw-rw---- 1 root dialout 4, 72 Dec 8 10:05 /dev/ttyS8 crw-rw---- 1 root dialout 4, 73 Dec 8 10:05 /dev/ttyS9 $ sudo cat /etc/group|grep koen adm:x:4:koen tty:x:5:koen dialout:x:20:koen cdrom:x:24:koen sudo:x:27:koen dip:x:30:koen plugdev:x:46:koen lpadmin:x:107:koen scanner:x:116:koen koen:x:1000: $ sudo which cu /usr/bin/cu $ cu -l /dev/ttyS0 -s 115200 Connected. (note: cu always says "Connected.", this doesn't mean anything) (also note: the baudrate, parity, et cetera... are correct; the cable is healthy and connected to the right serial port) $ sudo cu -l /dev/ttyS0 -s 115200 /usr/bin/cu: open (/dev/ttyS0): Permission denied /usr/bin/cu: /dev/ttyS0: Line in use $ sudo su - # cu -l /dev/ttyS0 -s 115200 /usr/bin/cu: open (/dev/ttyS1): Permission denied /usr/bin/cu: /dev/ttyS1: Line in use nothing can be found in any logs, and i don't see any way to debug this from userland. do we really need to hook up a kernel debugger to get a serial line working in a modern unix? to rule things out, i made a polkit action definition for this. logs confirmed the action definition worked. i tried the above scenarios with polkit's pkexec. it didn't make any difference. to rule things out, i tried making a pam exception for this (capabilities), by adding some lines to /etc/security/group.conf and creating /etc/pam.d/cu. it didn't make any difference, but i'm not sure my pam configuration was entirely correct. to rule things out, i started fiddling with /bin/stty (which shouldn't be needed). it didn't make any difference. for the record: $ sudo stty -a speed 38400 baud; rows 43; columns 124; line = 0; intr = ^C; quit = ^\; erase = ^?; kill = ^U; eof = ^D; eol = M-^?; eol2 = M-^?; swtch = M-^?; start = ^Q; stop = ^S; susp = ^Z; rprnt = ^R; werase = ^W; lnext = ^V; flush = ^O; min = 1; time = 0; -parenb -parodd cs8 hupcl -cstopb cread -clocal -crtscts -ignbrk brkint -ignpar -parmrk -inpck -istrip -inlcr -igncr icrnl ixon -ixoff -iuclc ixany imaxbel iutf8 opost -olcuc -ocrnl onlcr -onocr -onlret -ofill -ofdel nl0 cr0 tab0 bs0 vt0 ff0 isig icanon iexten echo echoe echok -echonl -noflsh -xcase -tostop -echoprt echoctl echoke $ sudo stty -g 6d02:5:4bf:8a3b:3:1c:7f:15:4:0:1:ff:11:13:1a:ff:12:f:17:16:ff:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0 $ sudo stty -F /dev/ttyS0 speed 115200 (this is interesting! apparently baudrate was set by cu?) -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1087519 Title: Serial port ttyS4 doesn't work in 12.04 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+bug/1087519/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
