Re: Possible bug in 8250.c

From: Jiri Slaby
Date: Fri Aug 19 2011 - 15:02:00 EST


On 08/19/2011 07:44 PM, Ivica Mikec wrote:
>
> Hi!
>
>
> I noticed a problem in 8250.c.
>
> My board has only one UART port, and is 16550 compatible, so in function serial8250_interrupt I see that serial_in function is called twice. Second time, code "else if (end == NULL)" is executed and function return IRQ_NONE. This causes an entry in /proc/irq/spurious:
>
> count 239
> unhandled 1
> last_unhandled 4294700846 ms
>
> But this is not a spurious interrupt.

How did you find out? Have you checked that the port signals that it
raised an interrupt? I.e. does it go through the 'if (!(iir &
UART_IIR_NO_INT))' branch?

What other devices are bound to the same interrupt? Attach /proc/interrupts.

regards,
--
js
suse labs
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/