I have a Celeron ETX processor module with a Winbond W83627HF SuperIO chip, providing two 16550A compatible UARTs, which connects over LPC to an 82801DB south bridge. I'm only using the first serial port at the moment. The modules 8250 and 8250_pnp are loaded, and the serial port is on standard resources (irq 4). After one of my complex applications at work runs for a few minutes, the serial port suddenly stops. The UART IIR indicates an interrupt is pending, and the LSR indicates data is waiting to be received (as well as sent), but the interrupt handler is not being called. If while it's stuck I reset the enabled interrupts (save IER, clear IER, restore IER) the I/O resumes. I don't see anything wrong with the way the UART is being serviced. The kernel is patched to 2.6.25.11, configured by Debian as SMP, no PREEMPT, shared IRQ (nothing else is on irq 4) and without any external modules loaded. It's a Celeron without any HT or multiple cores, so it's uniprocessor. I haven't been able to make a simple test case. The real program is kind of a loopback that's continuously receiving and sending data at 115200 8N1 with no flow control. The full data rate isn't being used, and I'm not getting any overruns (until it stalls). A simple loopback program doesn't demonstrate the problem, but the real application runs into it every time within 10 minutes (usually under 5). -- Jeff DeFouw <jeffd@xxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
