On Thu, 2012-04-05 at 14:25 -0500, ron r wrote: > I am using Fedora 16. Using "ls -l /dev/ttyS*" shows 4 "devices" > with "crw-rw----" for each one. So then I looked on google for > setting serial permissions, and entered "chmod a+rw /dev/ttyS0" as > root and the serial port now works! > That was a nice victory, but the line must be entered at each boot. > (Is there a solution to that?) > I have this file: ==============File 99-local.rules start=============== # # Locally defined rules. # # # Give world read/write access to ttyS* and ttyUSB* serial devices # KERNEL=="tty[A-Z]*", GROUP="uucp", MODE="0666" ===============File 99-local.rules end================ installed in /etc/udev/rules.d/ There was no file with that name installed by default in my system but check your system before dropping it in so you don't accidentally clobber anything. I use the 99 prefix because these rules files are applied in name sort order and I want to be sure that the device files have been created before trying to override their access permissions. Another thing to check: the group assignments for serial port devices may have changed since I wrote that file, which was for the first Fedora that used UDEV serial port management, possibly Fedora 12 but could be earlier. Before you install it, run "ls -l /dev/ttyS*" and, if the group isn't "uucp" (it may be "tty"), replace that string with the group name F16 is using. I know that this time round I just dropped 99-local.rules in without checking the group name and appended " 8250.nr_uarts=5" to the GRUB_CMDLINE_LINUX parameter in /etc/default/grub so the kernel knew it was dealing with five serial ports: I have one on the motherboard and another four on a multiport serial card. Then I rebooted so the kernel parameter took effect and it all worked. Martin
