RaZberry UART serial8250: too much work for irq4

[rysiek]

Hi,

I have a problem with RaZberry connected by UART to ECS LIVIA Mini PC (Intel Celeron based).

I'm using OpenZWave library and every thing works fine, but after few hours (when polling is enabled) I receive message from kernel (kern.log):
Aug 17 09:28:06 system kernel: [87845.250774] serial8250: too much work for irq4
And after this I have to reconnect to RaZberry contoller.

I have a simple Z-Wave network with 4 devices and one controller. I setup polling for one device value for every other second and every time I get this message in kern.log and I have to restart application.

I have checked:
1. Communcation with RaZberry contoller is very simple/slow it is about 40 bytes send and received for each other second (about 160 bps).
2. No other device uses IRQ4:
root@system:~# setserial /dev/ttyS0
/dev/ttyS0, UART: 16550A, Port: 0x03f8, IRQ: 4

root@system:~# cat /proc/interrupts
CPU0 CPU1
0: 27 0 IO-APIC 2-edge timer
4: 359853 0 IO-APIC 4-edge serial
8: 0 0 IO-APIC 8-fasteoi rtc0
9: 0 0 IO-APIC 9-fasteoi acpi
...

I'm not sure what to do.
I have recorded every byte send and received from RaZberry contoller... I can attach it if needed.

[PoltoS]

Looks like OS/kernel configuration problem. Please check kernel configuration. Hard to support more as we have never tested this PC with this OS.

Certainly it is not RaZberry related as it is just a simple UART communication board.