Hello, I'm using a Gene4310-SBC together with an 8-Port serial interface card (PM-1028 [2xTL16C554A]) with Linux 2.4.20. The 8 ports use a shared interrupt (IRQ 7). On some SBC's the system works perfectly; but some configurations make trouble (I presume the system works with old Gene4310 (Rev.1.2 ) whereas Gene4310 Rev.1.4 together PM-1028 in some cases don't work.)
The kernel initializes the serial interfaces without problems and my application opens the ports. If data arrive, /proc/interrupts tells me, that interrupts were triggered but the app doesn't get any data from the port(s). (There runs only my app on the machine.)
There are not interrups counted when I remove the serial cable. Changing the IRQ-line has no effect. Also the IO-ports are available for my serial card...
If I power off and on the machine all seems to work perfectly, but after powering off, waiting some minutes and powering on the problem occurs...
I'm very thankful for every advice!
Juergen