On Dec 29 2006 12:41, Sergei Organov wrote: > >It seems that the kernel has some problems/races in opening/closing of >serial ports. Simple C program below just opens/closes a port in a loop: >[..] >I've noticed 2 problems running this program. I run 2.6.19.1 smp kernel >(I've also tested Debian 2.6.18.3 kernel, and it has the same issues) on >hyper-threaded Pentium 4 CPU. Also happens on 2.6.18.5 on AMD AXP2000 (UP, CONFIG_SMP=y), standard x86 pc serial port serial8250: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A 00:09: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A >1. When I run the program, I begin to get "irq 4: nobody cared" in dmesg even > though the port is not connected (idle). Please find relevant part of dmesg > below. Running said program repeatedly produces one stack trace every 4 seconds (CONFIG_HZ=100). Maybe knowing this interval helps finding the problem. [ 9545.167750] Disabling IRQ #4 [ 9549.599704] Disabling IRQ #4 [ 9554.034803] Disabling IRQ #4 [ 9558.455093] Disabling IRQ #4 [ 9562.876508] Disabling IRQ #4 -`J' -- - 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