Ubuntu kernel 2.6.24 with Fintek F81216 on NOVA 9452 MoBo

James jamessteward at optusnet.com.au
Fri Apr 24 00:01:47 UTC 2009


I'm not sure if this is a bug as such, no kernel oops, but unsupported
hardware, or misconfiguration perhaps?  Let me explain...

I've got a NOVA-9452 MoBo, and as far as I can tell it has a Fintek
F81216DG quad UART chip on a LPC bus.

The BIOS reports that the board has 2 standard UARTs at 3f8/irq4 and
2f8/irq3, then 4 more UARTs at 3e8, 2e8, 2f0 and 2e0.  There is no IRQ
assignment in the BIOS for these 4 UARTs.

I've installed Ubuntu 8.04 on to a 4GB CF with net install cli only, and
it works a charm.

With the standard Ubuntu 8.04.2 kernel (2.6.24-23-generic), there are
only 4 serial ports supported.

I installed the kernel sources, started with the generic config, and
made it capable of supporting 8 serial ports (I thought the standard 4
plus the Fintek 4 = 8).

Rebuilt and ran the new kernel,, with extra serial port

Now dmesg reports the following.

[    0.000000] Initializing cgroup subsys cpuset
[    0.000000] Initializing cgroup subsys cpu
[    0.000000] Linux version (root at rti8000lin) (gcc version 4.2.4 (Ubuntu 4.2.4-1ubuntu3)) #3 SMP Fri Apr 24 08:34:09 EST 2009 (Ubuntu 2.6.24-23.52-generic)


[  423.904057] Serial: 8250/16550 driver $Revision: 1.90 $ 8 ports, IRQ sharing enabled
[  423.904269] serial8250: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A
[  423.904469] serial8250: ttyS1 at I/O 0x2f8 (irq = 3) is a 16550A
[  423.904665] serial8250: ttyS2 at I/O 0x3e8 (irq = 4) is a 16550A
[  423.904864] serial8250: ttyS3 at I/O 0x2e8 (irq = 3) is a 16550A
[  423.905457] 00:06: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A
[  423.905736] 00:07: ttyS1 at I/O 0x2f8 (irq = 3) is a 16550A
[  423.906022] 00:09: ttyS2 at I/O 0x3e8 (irq = 11) is a 16550A
[  423.906291] 00:0a: ttyS3 at I/O 0x2e8 (irq = 0) is a 16550A
[  423.906561] 00:0b: ttyS4 at I/O 0x2f0 (irq = 0) is a 16550A
[  423.906827] 00:0c: ttyS5 at I/O 0x2e0 (irq = 0) is a 16550A

This looks very odd to me.  IRQ 11 is supposed to be reserved in the
BIOS, and IRQ 0 ??

At least now it detects the all available serial ports.

I've done some google searching for the Fintek device and come across


Which leaves me somewhat confused.

Does anyone have some advice to help me get these Fintek UARTs working,
or at least which list/forum to ask?

Please reply to me direct, as I'm not a subscriber to this list...


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