From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755571Ab1HSTB5 (ORCPT ); Fri, 19 Aug 2011 15:01:57 -0400 Received: from mail-fx0-f46.google.com ([209.85.161.46]:50578 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755209Ab1HSTBw (ORCPT ); Fri, 19 Aug 2011 15:01:52 -0400 Message-ID: <4E4EB31B.70709@suse.cz> Date: Fri, 19 Aug 2011 21:01:47 +0200 From: Jiri Slaby User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:6.0) Gecko/20110812 Thunderbird/6.0 MIME-Version: 1.0 To: mikeci@acm.org CC: linux-kernel@vger.kernel.org Subject: Re: Possible bug in 8250.c References: <26505.1313775887@sonic.net> In-Reply-To: <26505.1313775887@sonic.net> X-Enigmail-Version: 1.3 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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