From owner-freebsd-stable@FreeBSD.ORG Tue Jun 3 19:04:23 2008 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 81B7A1065673; Tue, 3 Jun 2008 19:04:23 +0000 (UTC) (envelope-from peterjeremy@optushome.com.au) Received: from mail04.syd.optusnet.com.au (mail04.syd.optusnet.com.au [211.29.132.185]) by mx1.freebsd.org (Postfix) with ESMTP id 154AD8FC1E; Tue, 3 Jun 2008 19:04:22 +0000 (UTC) (envelope-from peterjeremy@optushome.com.au) Received: from server.vk2pj.dyndns.org (c122-106-215-175.belrs3.nsw.optusnet.com.au [122.106.215.175]) by mail04.syd.optusnet.com.au (8.13.1/8.13.1) with ESMTP id m53J4J3x003937 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Wed, 4 Jun 2008 05:04:20 +1000 Received: from server.vk2pj.dyndns.org (localhost.vk2pj.dyndns.org [127.0.0.1]) by server.vk2pj.dyndns.org (8.14.2/8.14.2) with ESMTP id m53J4JSE084691; Wed, 4 Jun 2008 05:04:19 +1000 (EST) (envelope-from peter@server.vk2pj.dyndns.org) Received: (from peter@localhost) by server.vk2pj.dyndns.org (8.14.2/8.14.2/Submit) id m53J4IED084690; Wed, 4 Jun 2008 05:04:18 +1000 (EST) (envelope-from peter) Date: Wed, 4 Jun 2008 05:04:18 +1000 From: Peter Jeremy To: John Baldwin Message-ID: <20080603190418.GP1028@server.vk2pj.dyndns.org> References: <20080603070840.GH1028@server.vk2pj.dyndns.org> <200806031021.35416.jhb@freebsd.org> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="bgLLobvf7eP6VP5c" Content-Disposition: inline In-Reply-To: <200806031021.35416.jhb@freebsd.org> X-PGP-Key: http://members.optusnet.com.au/peterjeremy/pubkey.asc User-Agent: Mutt/1.5.17 (2007-11-01) Cc: freebsd-stable@freebsd.org Subject: Re: Interrupt storm with shared interrupt on digi(4) X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 03 Jun 2008 19:04:23 -0000 --bgLLobvf7eP6VP5c Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On 2008-Jun-03 10:21:35 -0400, John Baldwin wrote: >> In the past, I have managed to avoid the problem by putting the Digi >> card on a dedicated interrupt. For reasons I don't understand, this >> appears to mask the problem. > >That is because we leave interrupts masked until it gets an interrupt hand= ler. >Since digi(4) doesn't register a handler, we leave the interrupt masked=20 >unless some other device is sharing the same interrupt and registers a=20 >handler. This is what I assumed but doesn't explain how having two digi boards that share an interrupt with each other but nothing else winds up with an interrupt storm. I will have to investigate further... >No. Even better would be if there was a way to disable interrupt generati= on=20 >in the digi(4) driver via some register. Agreed. Unfortunately, the only documentation is the Linux driver and it doesn't appear to initialise the digi board any differently to FreeBSD. >> Alternatively, can anyone suggest how I can disable or mask a specified >> PCI interrupt? > >The problem is that in this case you have another driver that is using tha= t=20 >interrupt, so if you completely mask the interrupt the other driver will s= top=20 >getting interrupts and likely stop working. I agree that this approach is a hack - but it will let me work around the problem on the problematic system. BTW, your MUA's list-reply configuration don't recognize that freebsd-stable@ and stable@ are aliases. --=20 Peter Jeremy Please excuse any delays as the result of my ISP's inability to implement an MTA that is either RFC2821-compliant or matches their claimed behaviour. --bgLLobvf7eP6VP5c Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.9 (FreeBSD) iEYEARECAAYFAkhFlbIACgkQ/opHv/APuIdXGwCeMw1WvTkZDxeuokFx52bH44hn PBgAmwXo6x/zYHzpEpfbwXlQOAjZKnFa =m39y -----END PGP SIGNATURE----- --bgLLobvf7eP6VP5c--