From mboxrd@z Thu Jan 1 00:00:00 1970 From: Robert Hancock Subject: Re: IRQ 15 not assigned, but still unable to use it - in MSDOS it works Date: Thu, 17 Jun 2010 21:01:54 -0600 Message-ID: <4C1AE1A2.405@gmail.com> References: <4C18B5CB.4060707@rdsoftware.de> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail-iw0-f174.google.com ([209.85.214.174]:52333 "EHLO mail-iw0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755821Ab0FRDB5 (ORCPT ); Thu, 17 Jun 2010 23:01:57 -0400 Received: by iwn9 with SMTP id 9so584669iwn.19 for ; Thu, 17 Jun 2010 20:01:56 -0700 (PDT) In-Reply-To: <4C18B5CB.4060707@rdsoftware.de> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Erik Rull Cc: linux-ide@vger.kernel.org On 06/16/2010 05:30 AM, Erik Rull wrote: > Hi all, > > I've worked a lot on bringing the IRQ 15 to work for my embedded system > but it still fails. > > My kernel is the 2.6.29.4 - I've already updated from 2.6.23.3 because > there were some bugs in some ata drivers. > My system is a embedded system with Intel ATOM CPU and Intel 965 chipset. > I need to access some very old ISA-Bus boards. Before I used a Pentium-M > Board that worked perfect. > The new board seems to have problems disabling the IRQ 15 in linux. BIOS > has IRQ 15 reserved for legacy hardware and the IDE port behind it is > disabled - so IRQ15 should be really free. > The 2.6.23.3 found an IDE device and said afterwards that it is disabled > but kept the resources assigned without releasing them - so I was not > able to use the IRQ15 with my own software. > With the 2.6.29.4 I don't get this any longer but the IRQ15 doesn't work > either. Other interrupts are fine (5 or 10) but they are already used by > other hardware components. > Now the interesting part: in MSDOS I'm able to see the IRQ15 from the > ISA board as a source.... > > So I think that linux somewhere takes the IRQ15 and does not allow me to > use it - and IRQ sharing seems not to be possible in this case. > > I need some ideas where to continue my search - I think that it is > somewhere in the libata that blocks this interrupt. /proc/interrupts > shows up no interrupt neither that #15 is used. If no driver attaches to the device and nothing is reported in /proc/interrupts then nothing should be blocking the interrupt driver-wise. I suspect the problem might be elsewhere, like the IRQ routing or something..