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From: Jiri Slaby <jslaby@suse.cz>
To: mikeci@acm.org
Cc: linux-kernel@vger.kernel.org
Subject: Re: Possible bug in 8250.c
Date: Fri, 19 Aug 2011 21:01:47 +0200	[thread overview]
Message-ID: <4E4EB31B.70709@suse.cz> (raw)
In-Reply-To: <26505.1313775887@sonic.net>

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

  reply	other threads:[~2011-08-19 19:01 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-08-19 17:44 Possible bug in 8250.c Ivica Mikec
2011-08-19 19:01 ` Jiri Slaby [this message]
  -- strict thread matches above, loose matches on Subject: below --
2011-08-20  0:58 Ivica Mikec
2011-08-20 16:21 ` Alan Cox

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