Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757362Ab0KOPRP (ORCPT ); Mon, 15 Nov 2010 10:17:15 -0500 Received: from gate.crashing.org ([63.228.1.57]:34092 "EHLO gate.crashing.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754072Ab0KOPRO convert rfc822-to-8bit (ORCPT ); Mon, 15 Nov 2010 10:17:14 -0500 Subject: Re: [PATCH v2] fsldma: add support to 36-bit physical address Mime-Version: 1.0 (Apple Message framework v1081) Content-Type: text/plain; charset=us-ascii From: Kumar Gala In-Reply-To: Date: Mon, 15 Nov 2010 09:16:57 -0600 Cc: Li Yang , dan.j.williams@intel.com, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8BIT Message-Id: <3B38AD35-39A2-4A54-8109-65D6DE436227@kernel.crashing.org> References: <1289477789-10651-1-git-send-email-leoli@freescale.com> <54AAF9B7-9533-45B8-9C49-A964203AF707@kernel.crashing.org> To: Timur Tabi X-Mailer: Apple Mail (2.1081) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 887 Lines: 17 On Nov 13, 2010, at 4:43 PM, Timur Tabi wrote: > On Thu, Nov 11, 2010 at 5:56 AM, Kumar Gala wrote: > >> Is there any reason we shouldn't set DMA_BIT_MASK(64) since the DMA block programming model allows the address to be 64-bits? > > Can you explain that? The DMA registers only have room for 36 bits > for the physical address. The programming model (if you look at the free-space in the registers and data structures) supports a 64-bit address. I'm trying to avoid changing the driver in the future if we have >36-bit. However this is such a minor worry that I'll stop and just ack the patch as is. - k-- 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/