On Tue, Oct 18, 2016 at 11:40:04AM -0500, Nathan Zimmer wrote: > 3.7.0 > cat /sys/bus/pnp/drivers/serial/*/resources > state = active > io 0x2f8-0x2ff > irq 12 > dma disabled > > 3.6.0 > :~ # cat /sys/bus/pnp/drivers/serial/*/resources > cat: /sys/bus/pnp/drivers/serial/*/resources: No such file or directory irq 12 for ttyS1? That should be irq 3. The bios is putting bogus information in pnp. Maybe there is rubbish in the bios setup or maybe it's fixed in a newer bios update. So before this change, the kernel would assume irq 3. After this change, the kernel first uses the information in pnp to see where the serial port is. It gets told that it's irq 12 and presumably it runs into all sorts of problems then. If memory serves that's the irq for the ps/2 mouse. The interesting bit is in 3.6.0: setserial /dev/ttyS1, UART: 16550A, Port: 0x02f8, IRQ: 3 becomes in 3.7.0: setserial /dev/ttyS1, UART: 16550A, Port: 0x02f8, IRQ: 12 You should be able to set the right irq with setserial, but obviously that doesn't help you if it fails in early boot. It's not immediately obvious to me what can be done in the kernel for this. Maybe the dmesg output could inspire, thanks. Sean -- 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
