Q: Serial port using IRQ 5

Q: Serial port using IRQ 5

Post by Wingyuen Po » Thu, 13 Jan 1994 05:39:58



Hi,

I would like to set up my internal modem on Port (0x3e8) *IRQ  (5)* .

I installed the Slackware 1.1.1 distribution whose installation script
prompted me for the COM (or UNIX equivalent) port number but not the
hardware specs. On bootup, Linux reports "tty02 at 0x3e8 (IRQ =
 4) is a 8250. (in fact, my Digicom modem is supposed to be 16550 alike)

Now, I think I am know why seyon has a most unusual behavior: it dials
out alright, it negotiates alright, the time button lights up (blackens,
actually :-) ), but no hint that Seyon realizes it has connected to the
outside - the countdown continues, and in another 10s, it redials! Of
course - the CD signal is activated on connection, but the CONNECT string
never gets across to the OS properly, and so Seyon waits, and waits, and
waits.....

I did a
"cat > /dev/cua2
 atz              "
and the following message appeared on the screen
"tpqic02: unexpected interrupt, stat == ff "
(I have no tape drive) (perhaps IRQ 5 is usually used for tape drives ??)

Can someone please give me counsel on how I should rectify this little PC
problem.

Thanxs so very much!

 -------    /////////     /////    /////    ////    ///  -----
 ------    ////    //   //   //  //   //   ////    //   ------
 ----    //// /////    //   //  //   //  /// //  ///   -------
       ////           /////    /////   ///   /////   you're most welcome!

 
 
 

Q: Serial port using IRQ 5

Post by Tracer Bullet P. » Thu, 13 Jan 1994 12:22:30


You need to edit your serial.c file (either in kernel/chr-drv
or drivers/chr-drv  (i think)) there sould be some documentation
about some defines you can put in and you need to add
#define  CONFIG_AUTO_IRQ
this will let the kernel figure out what irqs are used
once the modem's irq is know correctly it should work fine.

btw this is what I had to to for my modem.

Gene E. Scogin

 
 
 

Q: Serial port using IRQ 5

Post by Ian Strub » Thu, 13 Jan 1994 15:32:53



: You need to edit your serial.c file (either in kernel/chr-drv
: or drivers/chr-drv  (i think)) there sould be some documentation
: about some defines you can put in and you need to add
: #define  CONFIG_AUTO_IRQ
: this will let the kernel figure out what irqs are used
: once the modem's irq is know correctly it should work fine.

I have tried editing my serial.c file so that there is a #define CONFIG_AUTO_IRQ
line in there, but for some reason irq 5 is not being detected.   I have messed
around a few times and recompiled three times but to now avail.   Is that all you have to change in serial.c?

Ian
--

 
 
 

Q: Serial port using IRQ 5

Post by Joel M. Hoffm » Fri, 14 Jan 1994 01:18:12




>: You need to edit your serial.c file (either in kernel/chr-drv
>: or drivers/chr-drv  (i think)) there sould be some documentation
>: about some defines you can put in and you need to add
>: #define  CONFIG_AUTO_IRQ
>: this will let the kernel figure out what irqs are used
>: once the modem's irq is know correctly it should work fine.

>I have tried editing my serial.c file so that there is a #define
CONFIG_AUTO_IRQ
>line in there, but for some reason irq 5 is not being detected.   I
have messed
>around a few times and recompiled three times but to now avail.   Is

that all you have to change in serial.c?

No.  You will see a table of serial entries that looks something like
this, from my serial.c:

struct async_struct rs_table[] = {
        /* UART CLK   PORT IRQ     FLAGS        */
        { BASE_BAUD, 0x3F8, 4, STD_COM_FLAGS },         /* ttyS0 */
        { BASE_BAUD, 0x2F8, 3, STD_COM_FLAGS },         /* ttyS1 */
        { BASE_BAUD, 0x3E8, 5, STD_COM_FLAGS },         /* ttyS2 */
        { BASE_BAUD, 0x238, 9, STD_COM4_FLAGS },        /* ttyS3 */

        [etc.]

Notice the PORT and IRQ settings.  That's what you want to change.  (I
don't know why FLAGS is different for ttyS3.  Maybe that's why it's
not working....

Hope this helps.

-Joel

--
-----------------------------------------------------------------------------
|_|~~ Germany, Europe. 1943.    "The diameter of the bomb was 30 centimeters,
__|~| 16 Million DEAD.           and the diameter of its destruction, about 7
                                meters, and in it four killed and 11 wounded.
 cnc  Bosnia, Europe. 1993.     And around these, in a larger circle of  pain
 cnc  HOW MANY MORE?          and time,  are scattered two  hospitals and one
                          cemetery.   But the young woman who was  buried  in
                    the place from where she came, at a distance of more than
             than 100 kilometers, enlarges the circle considerably.   And the
      lonely man who is mourning her death in a distant  country incorporates
into the circle the whole world.  And I won't speak of the cry of the orphans
that reaches God's chair and from there makes the circle endless and godless."
-----------------------------------------------------------------------------

 
 
 

Q: Serial port using IRQ 5

Post by Harald Mi » Wed, 19 Jan 1994 03:04:13



: > You need to edit your serial.c file (either in kernel/chr-drv
: > or drivers/chr-drv  (i think)) there sould be some documentation
: > about some defines you can put in and you need to add
: > #define  CONFIG_AUTO_IRQ
: > this will let the kernel figure out what irqs are used
: > once the modem's irq is know correctly it should work fine.

Yes, and you will have to do this everytime you upgrade your kernel. Why
don't you folks simply call `setserial` in your rc.local?

Here's my call:

# set serial devices
if [ -x /etc/setserial ]; then
        /etc/setserial /dev/ttyS1 SPD_HI                # 16550A
        /etc/setserial /dev/ttyS2 0x03e8 5 SPD_HI       # 16550A
        /etc/setserial /dev/ttyS3 0x02e8 2
fi

Ciao,
hm

--

 
 
 

Q: Serial port using IRQ 5

Post by Ian Strub » Thu, 20 Jan 1994 01:40:18


Thanks for all the help.  I ended up grabbing setserial off of sunsite and
now everyone is happy with their irq's.  I have even passed this info on to
a few other people already.  So it is going to good use :)

Ian

--

 
 
 

1. using setserial to change irq on serial port

I have a SuSE 6.2 Linux installation on a dual processor PII 300 box. The
modem is ISA and on COM3. In the standard setting the irq on the port in
question would like to be irq 4. It needs to be 5. I have tried to use

setserial /dev/ttyS2 irq 5

(as root), but it comes back with
"Operation not permitted"
Permissioning as such should not be a problem since I attempt this as
root. Even worse, if I try to call setserial at boot time through the
relevant script in /etc/rc.d/serial
I get the same negative result. Anybody any idea what may be causing this
goofy behaviour of setserial, or any other way to reset my IRQ on that
port ?

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