Serial Driver and RS485 problem (Debian Etch/ 2.6.18-6)
 

I'm new here, so... Hi everyone!

The machine is a Mini PC with 4 serial port:
-ttyS0
-ttyS1
-ttyS2
for RS232 connection

and
-ttyS3
for RS232 / RS485 Connection (Selection is done by internal jumpers that enable a SP485EC chip)

on Debian I can use port ttyS0 and ttyS1 (RS232) without problem. ttyS2 is not on the rear panel (I don't know where it is...) so I can't use it. The last port, ttyS3, is recognized by the OS but I can't send or receive anything neither via RS485 nor via RS232.

On a Windows OS I can the fourth port ttyS3 (COM4) via RS485 and RS485.

I'm very confused: I tried a lot of software like GtkTerm, CuteCom, Minicom, scope.... but nothing!

Some reports..


debian:/home/jbox01# lspci
00:00.0 Host bridge: Intel Corporation 82852/82855 GM/GME/PM/GMV Processor to I/O Controller (rev 02)
00:00.1 System peripheral: Intel Corporation 82852/82855 GM/GME/PM/GMV Processor to I/O Controller (rev 02)
00:00.3 System peripheral: Intel Corporation 82852/82855 GM/GME/PM/GMV Processor to I/O Controller (rev 02)
00:02.0 VGA compatible controller: Intel Corporation 82852/855GM Integrated Graphics Device (rev 02)
00:02.1 Display controller: Intel Corporation 82852/855GM Integrated Graphics Device (rev 02)
00:1d.0 USB Controller: Intel Corporation 82801DB/DBL/DBM (ICH4/ICH4-L/ICH4-M) USB UHCI Controller #1 (rev 02)
00:1d.1 USB Controller: Intel Corporation 82801DB/DBL/DBM (ICH4/ICH4-L/ICH4-M) USB UHCI Controller #2 (rev 02)
00:1d.2 USB Controller: Intel Corporation 82801DB/DBL/DBM (ICH4/ICH4-L/ICH4-M) USB UHCI Controller #3 (rev 02)
00:1d.7 USB Controller: Intel Corporation 82801DB/DBM (ICH4/ICH4-M) USB2 EHCI Controller (rev 02)
00:1e.0 PCI bridge: Intel Corporation 82801 PCI Bridge (rev 82)
00:1f.0 ISA bridge: Intel Corporation 82801DB/DBL (ICH4/ICH4-L) LPC Interface Bridge (rev 02)
00:1f.1 IDE interface: Intel Corporation 82801DB (ICH4) IDE Controller (rev 02)
00:1f.3 SMBus: Intel Corporation 82801DB/DBL/DBM (ICH4/ICH4-L/ICH4-M) SMBus Controller (rev 02)
00:1f.5 Multimedia audio controller: Intel Corporation 82801DB/DBL/DBM (ICH4/ICH4-L/ICH4-M) AC'97 Audio Controller (rev 02)
01:04.0 Ethernet controller: Intel Corporation 82557/8/9 [Ethernet Pro 100] (rev 10)
01:08.0 Ethernet controller: Intel Corporation 82801DB PRO/100 VM (LOM) Ethernet Controller (rev 82)
debian:/home/jbox01#

from dmsg:
[...]
Serial: 8250/16550 driver $Revision: 1.90 $ 4 ports, IRQ sharing enabled
serial8250: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A
serial8250: ttyS1 at I/O 0x2f8 (irq = 3) is a 16550A
serial8250: ttyS2 at I/O 0x3e8 (irq = 4) is a 16550A
serial8250: ttyS3 at I/O 0x2e8 (irq = 3) is a 16550A
00:07: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A
00:08: ttyS1 at I/O 0x2f8 (irq = 3) is a 16550A
00:09: ttyS2 at I/O 0x3e8 (irq = 10) is a 16550A
00:0a: ttyS3 at I/O 0x2e8 (irq = 11) is a 16550A
[...]


Any suggest would be very appreciated!
Best regards,
Giacomo Pennella