Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S267565AbUIULIM (ORCPT ); Tue, 21 Sep 2004 07:08:12 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S267566AbUIULIM (ORCPT ); Tue, 21 Sep 2004 07:08:12 -0400 Received: from clock-tower.bc.nu ([81.2.110.250]:62426 "EHLO localhost.localdomain") by vger.kernel.org with ESMTP id S267565AbUIULIH (ORCPT ); Tue, 21 Sep 2004 07:08:07 -0400 Subject: Re: [PATCH] ppc64: Fix __raw_* IO accessors From: Alan Cox To: Benjamin Herrenschmidt Cc: Linus Torvalds , Andrew Morton , Linux Kernel Mailing List , Petr Vandrovec In-Reply-To: <1095758630.3332.133.camel@gaston> References: <1095758630.3332.133.camel@gaston> Content-Type: text/plain Content-Transfer-Encoding: 7bit Message-Id: <1095761113.30931.13.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.6 (1.4.6-2) Date: Tue, 21 Sep 2004 11:05:32 +0100 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 894 Lines: 20 On Maw, 2004-09-21 at 10:23, Benjamin Herrenschmidt wrote: > Hi ! > > Linus, I don't know if you did that on purpose, but you removed the > "volatile" statement from the definition of the __raw_* IO accessors > on ppc64, which cause some real bad optisations to happen in some > fbdev's like matroxfb to happen (just imagine that matroxfb loops > reading an IO register waiting for a bit to change). Why is it using __raw if it cares about ordering and not using barriers ? Way back when the original definition was that __raw didnt do barriers. Thats why I2O for example uses __raw_ so that messages can be generated as efficiently as possible. - 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/