From mboxrd@z Thu Jan 1 00:00:00 1970 From: Russell King - ARM Linux Subject: Re: FOR COMMENT: void __iomem * and similar casts are Bad News Date: Thu, 4 Sep 2008 00:16:20 +0100 Message-ID: <20080903231620.GQ19980@flint.arm.linux.org.uk> References: <20080827220821.GE7227@flint.arm.linux.org.uk> <20080903203720.GV23085@atomide.com> <20080903210412.GJ19980@flint.arm.linux.org.uk> <200809031435.52620.david-b@pacbell.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from caramon.arm.linux.org.uk ([78.32.30.218]:42675 "EHLO caramon.arm.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752342AbYICXQi (ORCPT ); Wed, 3 Sep 2008 19:16:38 -0400 Content-Disposition: inline In-Reply-To: <200809031435.52620.david-b@pacbell.net> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: David Brownell Cc: Tony Lindgren , Eduardo Valentin , linux-omap@vger.kernel.org On Wed, Sep 03, 2008 at 02:35:52PM -0700, David Brownell wrote: > On Wednesday 03 September 2008, Russell King - ARM Linux wrote: > > - virtual addresses are pointer like. > > - physical addresses are integer like. > > > > So, if it's a physical address, it should be stored in an integer type > > large enough to contain it, and that means something like u32, or > > unsigned long. > > And to complete the puzzle: in the absense of IOMMU technologies > what's the difference between a "physical address" and a dma_addr_t? > (DMA addreses being integer-like.) That's a valid point, and related, but one which I don't wish to get into at present (mainly because it isn't a problem on current hardware.) I'm not out to solve world hunger at this point, just to shake out some of the real problems that OMAP currently suffers from, which we can use the standard compiler to find. That's why I'm trying to keep this thread narrowly focussed.