From patchwork Wed Jan 16 10:32:35 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Bottomley X-Patchwork-Id: 1987371 Return-Path: X-Original-To: patchwork-linux-mmc@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork2.kernel.org (Postfix) with ESMTP id 157F3DF2A2 for ; Wed, 16 Jan 2013 10:32:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758797Ab3APKcm (ORCPT ); Wed, 16 Jan 2013 05:32:42 -0500 Received: from bedivere.hansenpartnership.com ([66.63.167.143]:53730 "EHLO bedivere.hansenpartnership.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758752Ab3APKcl (ORCPT ); Wed, 16 Jan 2013 05:32:41 -0500 Received: from localhost (localhost [127.0.0.1]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id C94DA8EE0EF; Wed, 16 Jan 2013 02:32:39 -0800 (PST) Received: from bedivere.hansenpartnership.com ([127.0.0.1]) by localhost (bedivere.hansenpartnership.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id gK0PVdnFkX_k; Wed, 16 Jan 2013 02:32:39 -0800 (PST) Received: from [153.66.254.224] (accolon.hansenpartnership.com [46.65.52.191]) by bedivere.hansenpartnership.com (Postfix) with ESMTPSA id 9ED1D8EE0C9; Wed, 16 Jan 2013 02:32:37 -0800 (PST) Message-ID: <1358332355.2384.11.camel@dabdike.int.hansenpartnership.com> Subject: Re: [PATCH v2 1/1] block: blk-merge: don't merge the pages with non-contiguous descriptors From: James Bottomley To: Subhash Jadavani Cc: linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org, linux-mmc@vger.kernel.org, linux-arm-msm@vger.kernel.org, martin.petersen@oracle.com, asias@redhat.com, tj@kernel.org, linux-arm-kernel@lists.infradead.org, Russell King Date: Wed, 16 Jan 2013 10:32:35 +0000 In-Reply-To: <50F64AC1.3040304@codeaurora.org> References: <1358265681-25671-1-git-send-email-subhashj@codeaurora.org> <1358266794.10591.8.camel@dabdike.int.hansenpartnership.com> <50F64AC1.3040304@codeaurora.org> X-Mailer: Evolution 3.6.2 Mime-Version: 1.0 Sender: linux-mmc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org On Wed, 2013-01-16 at 12:07 +0530, Subhash Jadavani wrote: > Now consider this call stack from MMC block driver (this is on the ARmv7 > based board): > [ 98.918174] [] (v7_dma_inv_range+0x30/0x48) from > [] (dma_cache_maint_page+0x1c4/0x24c) > [ 98.927819] [] (dma_cache_maint_page+0x1c4/0x24c) from > [] (___dma_page_cpu_to_dev+0x14/0x1c) > [ 98.937982] [] (___dma_page_cpu_to_dev+0x14/0x1c) from > [] (dma_map_sg+0x3c/0x114) OK, so this is showing that ARM itself is making the assumption that the pages are contiguous in the page offset map. Fix this by doing the increment via the pfn, which will do the right thing whatever the memory model. Signed-off-by: James Bottomley --- -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index 6b2fb87..ab88c5b 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -809,7 +809,7 @@ static void dma_cache_maint_page(struct page *page, unsigned long offset, op(vaddr, len, dir); } offset = 0; - page++; + page = pfn_to_page(page_to_pfn(page) + 1); left -= len; } while (left); }