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Check Serial Port

Days ago I have some troubles with the serial port and any devices I switch on it weren't recognize.
After reserarching a little bit, I found different ways to check if the serial port of your computer doesn't work any more.

First you can check is the following:

root@carpc1:~# more /proc/tty/driver/serial
serinfo:1.0 driver revision:
0: uart:16550A port:000003F8 irq:4 tx:162 rx:0 RTS|DTR
1: uart:16550A port:000002F8 irq:3 tx:162 rx:0
2: uart:unknown port:000003E8 irq:4
3: uart:unknown port:000002E8 irq:3

Here, the serial port is present as we can see in the first line.

In the following example there is no serial port, ... something goes wrong:

root@ecar-demo2:~# more /proc/tty/driver/serial
serinfo:1.0 driver revision:
0: uart:unknown port:000003F8 irq:4
1: uart:unknown port:000002F8 irq:3
2: uart:unknown port:000003E8 irq:4
3: uart:unknown port:000002E8 irq:3

Obviously, althought the computer has a serial port, it is not recognized by the so. To be sure that the serial port stop working, we can check the interruptions of the so. In the following example, no interruption is assigned to the serial port so we can suspect than something goes wrong ...

ecar@ecar-demo2:~$ sudo more /proc/interrupts
CPU0
0: 415623 IO-APIC-edge timer
1: 141 IO-APIC-edge i8042
8: 3 IO-APIC-edge rtc
9: 0 IO-APIC-fasteoi acpi
14: 8698 IO-APIC-edge ide0
16: 0 IO-APIC-fasteoi libata
17: 28589 IO-APIC-fasteoi uhci_hcd:usb1, uhci_hcd:usb2, uhci_hcd:usb3, uhci_hcd:usb4, ehci_hcd:usb5
18: 151953 IO-APIC-fasteoi eth1
19: 0 IO-APIC-fasteoi VIA8237
NMI: 0
LOC: 415300
ERR: 0
MIS: 0

A correct configuration of the interruption could be the following example:

root@hostV:~# more /proc/interrupts
CPU0
0: 12787 XT-PIC-XT timer
2: 0 XT-PIC-XT cascade
4: 209 XT-PIC-XT serial
10: 0 XT-PIC-XT eth0
14: 40629 XT-PIC-XT ide0
15: 19 XT-PIC-XT ehci_hcd:usb1, ohci_hcd:usb2
NMI: 0
ERR: 0

Actually, we can see here that the serial port is present: 4: 209 XT-PIC-XT serial

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