Enabling a four-port serial card

David Scriven davidwriter at yahoo.com
Sat Jan 12 02:02:44 UTC 2008


Tom Horsley wrote:

>Did you add the kernel boot parameter in grub.conf? Mine looks like
>this:

>title Fedora (2.6.23.8-63.fc8)
>	root (hd0,2)
>	kernel /vmlinuz-2.6.23.8-63.fc8 ro root=LABEL=F8ROOT64 quiet 8250.nr_uarts=9
>	initrd /initrd-2.6.23.8-63.fc8.img

>The "9" as the value for 8250.nr_uarts tells the kernel to allocate slots
>for 9 serial ports in its internal tables. The default is only 4. I use
>9 to get the 1 native serial port on my motherboard plus the 8 ports in
>my 8 port card to work.

>(Of course if you are booting the Xen kernel, completely different trickery
>is required).

I fiddled around with this (I tried values of 5, 6, 7 & 8) until I found that this
title Fedora (2.6.23.9-85.fc8)
   root (hd0,1)
   kernel /vmlinuz-2.6.23.9-85.fc8 ro root=/dev/VolGroup00/LogVol00 quiet 8250.nr_uarts=8
   initrd /initrd-2.6.23.9-85.fc8.img

gave this:

ls -l /dev/ttyS*
crw-rw---- 1 root uucp 4, 64 2008-01-11 15:39 /dev/ttyS0
crw-rw---- 1 root uucp 4, 65 2008-01-11 16:00 /dev/ttyS1
crw-rw---- 1 root uucp 4, 66 2008-01-11 15:39 /dev/ttyS2
crw-rw---- 1 root uucp 4, 67 2008-01-11 15:39 /dev/ttyS3
crw-rw---- 1 root uucp 4, 68 2008-01-11 17:35 /dev/ttyS4
crw-rw---- 1 root uucp 4, 69 2008-01-11 16:00 /dev/ttyS5
crw-rw---- 1 root uucp 4, 70 2008-01-11 16:00 /dev/ttyS6
crw-rw---- 1 root uucp 4, 71 2008-01-11 16:00 /dev/ttyS7

/bin/setserial -ag /dev/ttyS*
/dev/ttyS0, Line 0, UART: unknown, Port: 0x03f8, IRQ: 4
        Baud_base: 115200, close_delay: 50, divisor: 0
        closing_wait: 3000
        Flags: spd_normal skip_test auto_irq

/dev/ttyS1, Line 1, UART: undefined, Port: 0x02f8, IRQ: 3
        Baud_base: 921600, close_delay: 50, divisor: 0
        closing_wait: 3000
        Flags: spd_normal skip_test auto_irq

/dev/ttyS2, Line 2, UART: unknown, Port: 0x03e8, IRQ: 4
        Baud_base: 115200, close_delay: 50, divisor: 0
        closing_wait: 3000
        Flags: spd_normal skip_test auto_irq

/dev/ttyS3, Line 3, UART: unknown, Port: 0x02e8, IRQ: 3
        Baud_base: 115200, close_delay: 50, divisor: 0
        closing_wait: 3000
        Flags: spd_normal auto_irq

/dev/ttyS4, Line 4, UART: 16550A, Port: 0x1030, IRQ: 21
        Baud_base: 115200, close_delay: 50, divisor: 0
        closing_wait: 3000
        Flags: spd_normal skip_test

/dev/ttyS5, Line 5, UART: 16550A, Port: 0x1028, IRQ: 21
        Baud_base: 115200, close_delay: 50, divisor: 0
        closing_wait: 3000
        Flags: spd_normal skip_test

/dev/ttyS6, Line 6, UART: 16550A, Port: 0x1020, IRQ: 21
        Baud_base: 115200, close_delay: 50, divisor: 0
        closing_wait: 3000
        Flags: spd_normal skip_test

/dev/ttyS7, Line 7, UART: 16550A, Port: 0x1018, IRQ: 21
        Baud_base: 115200, close_delay: 50, divisor: 0
        closing_wait: 3000
        Flags: spd_normal skip_test


with the four ports correctly assigned, BUT - alas I
can't get the ports to work. A Qt program that works
in Windows does not work in Linux - no communication.
I've tried echoing a command to S4-7 - no luck. Qt
(i.e. QIODevice & qextserialport) reports that the
ports are open when I try to open them, but thats it.

I've no idea what to do next, except to buy a different
serial card that works in both Linux and Windows - perhaps
it's something to do with the combination of motherboard
and serial card?

DS





      Looking for the perfect gift? Give the gift of Flickr! 

http://www.flickr.com/gift/




More information about the fedora-list mailing list