Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750768AbWEVLuu (ORCPT ); Mon, 22 May 2006 07:50:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750771AbWEVLuu (ORCPT ); Mon, 22 May 2006 07:50:50 -0400 Received: from dtp.xs4all.nl ([80.126.206.180]:30460 "HELO abra2.bitwizard.nl") by vger.kernel.org with SMTP id S1750768AbWEVLut (ORCPT ); Mon, 22 May 2006 07:50:49 -0400 Date: Mon, 22 May 2006 13:50:46 +0200 From: Rogier Wolff To: Alan Cox Cc: Linus Torvalds , Russell King , Andrew Morton , Andreas Mohr , florin@iucha.net, linux-kernel@vger.kernel.org, linux@dominikbrodowski.net Subject: Re: pcmcia oops on 2.6.17-rc[12] Message-ID: <20060522115046.GA23074@bitwizard.nl> References: <20060423192251.GD8896@iucha.net> <20060423150206.546b7483.akpm@osdl.org> <20060508145609.GA3983@rhlx01.fht-esslingen.de> <20060508084301.5025b25d.akpm@osdl.org> <20060508163453.GB19040@flint.arm.linux.org.uk> <1147730828.26686.165.camel@localhost.localdomain> <1147734026.26686.200.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1147734026.26686.200.camel@localhost.localdomain> Organization: BitWizard.nl User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1954 Lines: 42 On Tue, May 16, 2006 at 12:00:26AM +0100, Alan Cox wrote: > > So I would strongly argue that any driver that depends on getting an > > exclusive IRQ is buggy, not the PCMCIA layer itself, and that it would be > > a lot more productive to try to fix those drivers. > > It would certainly be a lot cleaner than this sort of code in the pcmcia > core right now. Want me to send a patch which only allows for SA_SHIRQ > and WARN_ON()'s for any driver not asking for shared IRQ ? The question I'm stuck with is: When is it valid to ask for a non-shared IRQ, and get back a shared one. Drivers that know that they don't work well if they are called by the "other" interrupt? I happen to know (ISA) hardware that CANNOT share an interrupt: It drives the IRQ line either high or low, and has a driver that will overpower anything else on that line. This sounds like a good place to me to have the driver request no sharing (*), and to prevent the IRQ line drivers getting in eachothers way, it would be nice if the kernel refused "early on" (i.e. before the stronger driver asserts: No IRQ pending, and the weaker one keeps trying to assert: "YES, I have an IRQ", and the weaker one slowly burning out). Or am I talking nonsense again? Roger. (*) The driver knows to allow sharing when it's talking to the PCI version of the card. -- ** R.E.Wolff@BitWizard.nl ** http://www.BitWizard.nl/ ** +31-15-2600998 ** *-- BitWizard writes Linux device drivers for any device you may have! --* Q: It doesn't work. A: Look buddy, doesn't work is an ambiguous statement. Does it sit on the couch all day? Is it unemployed? Please be specific! Define 'it' and what it isn't doing. --------- Adapted from lxrbot FAQ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/