Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758051Ab1EaH1N (ORCPT ); Tue, 31 May 2011 03:27:13 -0400 Received: from caramon.arm.linux.org.uk ([78.32.30.218]:47303 "EHLO caramon.arm.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751324Ab1EaH1L (ORCPT ); Tue, 31 May 2011 03:27:11 -0400 Date: Tue, 31 May 2011 08:26:50 +0100 From: Russell King - ARM Linux To: David Rientjes Cc: Dmitry Eremin-Solenikov , Nicolas Pitre , linux-arm-kernel , linux-kernel , Eric Miao , Samuel Ortiz Subject: Re: IrDA driver fails on PXA255 Message-ID: <20110531072650.GC21382@n2100.arm.linux.org.uk> References: <20110528205701.GA1788@doriath.ww600.siemens.net> <20110529215656.GA5576@n2100.arm.linux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.19 (2009-01-05) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1626 Lines: 35 On Mon, May 30, 2011 at 10:05:38PM -0700, David Rientjes wrote: > On Sun, 29 May 2011, Russell King - ARM Linux wrote: > > Again, no. This change has caused a load of previously working drivers > > to suddenly start failing without _any_ explanation why or even warning > > about the change. It needs to start off as a WARN_ON() so that stuff > > can be fixed, and then changed to a hard error. > > > > I haven't seen a "load" of error reports where this is causing an issue, > maybe it is much more popular on arm? > > This also isn't a hard error, admins should be able to enable > CONFIG_ZONE_DMA and rebuild so that the driver being loaded can get the > type of memory it is requesting. Just putting a WARN_ON() doesn't provide > any incentive to ever get this stuff fixed. I completely and violently disagree with your approach on this, and I'll continue to state that I believe you are wrong until you change your position. Enabling CONFIG_ZONE_DMA is not a fix, it's making the problem vanish off the radar. It will mean that the drivers using GFP_DMA will never get fixed up. I don't care whether you say "it's easy enough to audit the source code" - who's going to do that work? If you make the problem go away the answer to that will be NO ONE. Change it to be a soft WARN_ON for one release. Anything else will just result in the problem being IGNORED. -- 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/