Ashwin Ganti wrote: > Hi, > > We are having trouble with detecting the serial port > in Fedora Core 6. > > When I type the following command: > setserial -g /dev/ttyS* > > I get the following message: > > Cannot get serial info: Invalid argument > /dev/ttyS1: No such device or address > /dev/ttyS2: No such device or address > /dev/ttyS3: No such device or address > > However I tried this on two other machines running > Fedora core 4 and Fedora core 5 and both were able to > detect the serial port > A typical result is > /dev/ttyS0, UART: 16550A, Port: 0x03f8, IRQ: 4 > /dev/ttyS1, UART: unknown, Port: 0x02f8, IRQ: 3 > /dev/ttyS2, UART: unknown, Port: 0x03e8, IRQ: 4 > /dev/ttyS3, UART: unknown, Port: 0x02e8, IRQ: 3 > > We are not sure if this is a problem with Fedora Core > 6. > > Does anyone know how to fix this issue on Fedora 6? > Any help would be greatly appreciated. > > Thanks. > By default, udev creates 4 serial ports. The values shown in your listing above are the default values. From the output, I would guess that /dev/ttyS0 is the only one that is supported by the hardware. This because setserial reports a UART type for it. If /dev/ttyS1 was also on the motherboard, I would expect to also see a type 16550A UART listed. I have also found that the first 4 serial ports are normally reserved for ISA style serial ports. (Most serial ports found on the motherboard are mapped to the ISA bus, even if there are no ISA slots on the motherboard.) PCI serial ports are normally mapped to /dev/ttyS5 and higher. Some serial cards are mapped to other devices then ttyS#. Here is the setup on one of my systems. It has 2 serial ports on the motherboard and 2 on a PCI card. /dev/ttyS0, UART: 16550A, Port: 0x03f8, IRQ: 4 /dev/ttyS1, UART: 16550A, Port: 0x02f8, IRQ: 3 /dev/ttyS2, UART: unknown, Port: 0x03e8, IRQ: 4 /dev/ttyS3, UART: unknown, Port: 0x02e8, IRQ: 3 /dev/ttyS4, UART: 16550A, Port: 0x1090, IRQ: 21 /dev/ttyS5, UART: 16550A, Port: 0x1098, IRQ: 21 You will notice that /dev/ttyS2 and /dev/S3 show up as unknown UART type, but have the same I/O address and IRQ as you get. They are no real serial ports, even though there are device entries for them. I have not moved up to FC6 yet, so I can not check on it, but you can try running "modprobe serial" in case they changed the serial driver from being built-in to a module. I know it is built into the kernel in FC5. You can also try running "modprobe parport_serial". This may help if they are mapped as a PCI device instead of an ISA device. Mikkel -- Do not meddle in the affairs of dragons, for thou art crunchy and taste good with Ketchup!
