Serial troubles - Embedded

This is a discussion on Serial troubles - Embedded ; Hi !! I'm experimenting some strange behaviors for my Serial ISA pc card. I can read/write on both serials provided by isa card, but only one port works corretly, the remaining one is incredibly slow, while sharing the same configuration. ...

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Thread: Serial troubles

  1. Serial troubles

    Hi !!
    I'm experimenting some strange behaviors for my Serial ISA pc card.
    I can read/write on both serials provided by isa card, but only
    one port works corretly, the remaining one is incredibly slow,
    while sharing the same configuration.
    The original serial port is indeed perfecly working, as usual.
    This are my config:
    OS: Linux 192.168.0.15 2.4.27 #2 SMP Mo Aug 9 00:39:37 CEST 2004 i686 GNU/Linux
    cat /proc/interrupts
    CPU0
    0: 388291 XT-PIC timer
    1: 8 XT-PIC keyboard
    2: 0 XT-PIC cascade
    3: 0 XT-PIC ath0
    8: 1 XT-PIC rtc
    9: 2508 XT-PIC eth0, eth1
    11: 0 XT-PIC usb-ohci
    12: 11 XT-PIC PS/2 Mouse
    14: 32032 XT-PIC ide0
    15: 8 XT-PIC ide1
    NMI: 0
    LOC: 388265
    ERR: 0
    MIS: 0

    # cat /proc/ioports
    0000-001f : dma1
    0020-003f : pic1
    0040-005f : timer
    0060-006f : keyboard
    0070-007f : rtc
    0080-008f : dma page reg
    00a0-00bf : pic2
    00c0-00df : dma2
    00f0-00ff : fpu
    0170-0177 : ide1
    01f0-01f7 : ide0
    02e8-02ef : serial(set)
    0376-0376 : ide1
    03c0-03df : vga+
    03e8-03ef : serial(set)
    03f6-03f6 : ide0
    03f8-03ff : serial(auto)
    0cf8-0cff : PCI conf1
    c000-cfff : PCI Bus #01
    cc00-cc7f : Silicon Integrated Systems [SiS] SiS530 3D PCI/AGP
    d800-d8ff : D-Link System Inc RTL8139 Ethernet
    d800-d8ff : 8139too


    Serial driver is loaded as a module in a second stage, when i configure it
    by setserial, in order to match HW board configuration:
    After setserial intervention i can read:

    /proc/tty/driver# cat serial
    serinfo:1.0 driver:5.05c revision:2001-07-08
    0: uart:16550A port:3F8 irq:4 baud:9600 tx:0 rx:0
    2: uart:16550A port:3E8 irq:7 baud:9600 tx:49 rx:15 RTS|DTR
    3: uart:16550A port:2E8 irq:5 baud:9600 tx:119 rx:90 RTS|CTS|DTR|DSR|CD

    Number "0" is the basic serial port, while "2", "3" are my added ports.

    Where do I mistake ??

    Regards.
    PS: Serial Card model SUNIX 4031A ISA 16 bit 2S, 16C550 16FIFO

  2. Re: Serial troubles

    On 2005-04-23, Augusto Tenerelli wrote:

    > I'm experimenting some strange behaviors for my Serial ISA pc card.
    > I can read/write on both serials provided by isa card, but only
    > one port works corretly, the remaining one is incredibly slow,
    > while sharing the same configuration.


    In my experience, that has always been caused by misconfigured
    IRQ on the "slow" port.

    --
    Grant Edwards grante Yow! Everybody gets free
    at BORSCHT!
    visi.com

  3. Re: Serial troubles

    > In my experience, that has always been caused by misconfigured
    > IRQ on the "slow" port.


    How could I investigate ??

  4. Re: Serial troubles

    On 2005-04-24, Augusto Tenerelli wrote:

    >> In my experience, that has always been caused by misconfigured
    >> IRQ on the "slow" port.

    >
    > How could I investigate ??


    Good question. Here are some ideas:

    Take the board out and look at the IRQ jumper, then make sure
    no other ISA boards are configured to use that IRQ (use the
    PCI BIOS setup screen to reserve that IRQ for use by ISA
    boards). You did say it was an ISA serial board, right?

    You could try having setserial auto-discover the IRQ. I've
    never had a lot of luck with that.

    Just try configuring the driver for different IRQs until you
    find one that works.

    Remove as much other hardware from the bus as you can.

    --
    Grant Edwards grante Yow! I'm having
    at a tax-deductible
    visi.com experience! I need an
    energy crunch!!

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