cannot transfer packet via serial COM

saman_artorious · 04-17-2013, 08:13 AM

I have a Linux Ubuntu installed on an Intel Panel PC. My code did not run so, I checked out packet transfer using cutecom. It does OPEN THE PORT successfully, but no data is transfered. I plugged the serial port to my own PC, it works. One thing crossed my mind that the error could have error come from was checking the BIOS, how ttyS0-3 are allocated. Bios shows S0 to 11 or upper. All in AVAILABLE mode, I set S3 to RESERVED and checked via cutecom again. NO TRANSFER!. On the other hand, I DO NOT THINK that a driver should be installed for distinguishing the PC COMs, it SHOULD identify them automatically.

Code:

[    0.416691] ACPI: Power Button [PWRB]

[    0.416846] input: Power Button as /devices/LNXSYSTM:00/LNXPWRBN:00/input/input1

[    0.416859] ACPI: Power Button [PWRF]

[    0.443708] serial8250: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A

[    0.557357] serial8250: ttyS1 at I/O 0x2f8 (irq = 3) is a 16550A

[    0.708888] serial8250: ttyS2 at I/O 0x3e8 (irq = 4) is a 16550A

[    0.872588] serial8250: ttyS3 at I/O 0x2e8 (irq = 3) is a 16550A

[    1.015669] 00:06: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A

[    1.036607] 00:07: ttyS1 at I/O 0x2f8 (irq = 3) is a 16550A

[    1.060599] 00:08: ttyS2 at I/O 0x3e8 (irq = 11) is a 16550A

[    1.084589] 00:09: ttyS3 at I/O 0x2e8 (irq = 10) is a 16550A

[    1.085551] agpgart-intel 0000:00:00.0: detected gtt size: 262144K total, 262144K 

[   14.956323] serio: Serial port ttyS1

[   14.994250] serio: Serial port ttyS1

[   15.032073] input: Elo Serial TouchScreen as /devices/pnp0/00:07/tty/ttyS1/serio2/input

is there anything wrong with what dmesg shows? shall i change irqs using setirq? if yes, please write me an example of the details please.

David1357 · 04-17-2013, 06:27 PM

Quote:

Originally Posted by saman_artorious

My code did not run so

We need more information before we can help you. What is your "code" trying to do?

Quote:

Originally Posted by saman_artorious

I checked out packet transfer using cutecom. It does OPEN THE PORT successfully, but no data is transferred.

How are you verifying data transfer? If you are connecting two serial ports, you probably need a null modem cable. You can make your own by crossing pins 2 and 3 on a standard DB9 pass through cable.

Quote:

Originally Posted by saman_artorious

I plugged the serial port to my own PC, it works.

Which serial port are you connecting to your PC?

We really need more information before we can help you. If you can draw a simple diagram of the test setups you have tried, that will help a lot.

saman_artorious · 04-24-2013, 10:10 AM

The problem was with DB9 cable. But, the problem is only one of the COMs work. I mean, only one when connected, can transfer the packets. (using any available program like cutecom). The other three are inactive.
The PC I need to configure is an Intel PC Series, for Windows I was told that it has its own device driver program. when installed all other COms become available.
However, i think in linux all COMs are recognized. But I am definitely NOT SURE about it. before getting suspiscious about searching for the relevant linux version device driver, I think there may be something wrong with the IRQs.
see above, both S0 and S2 share irq=4 and S1, S3 share irq=3.
do you think the problem would be fixed if I reserve irq 1 2 3 4 in BIOS and set each to one of the devices at bootup?
(note that S1 is dedicated to touchscreen, as printed above).

let's find out the solution guys.