From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757519Ab0ANWge (ORCPT ); Thu, 14 Jan 2010 17:36:34 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752083Ab0ANWgb (ORCPT ); Thu, 14 Jan 2010 17:36:31 -0500 Received: from kroah.org ([198.145.64.141]:60583 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755787Ab0ANW2i (ORCPT ); Thu, 14 Jan 2010 17:28:38 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@kernel.org, stable-review@kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, Krzysztof Halasa , David Miller , Joerg Roedel , Greg Kroah-Hartman Subject: [PATCH 24/52] dma-debug: allow DMA_BIDIRECTIONAL mappings to be synced with DMA_FROM_DEVICE and Date: Thu, 14 Jan 2010 14:27:03 -0800 Message-Id: <1263508051-7868-24-git-send-email-gregkh@suse.de> X-Mailer: git-send-email 1.6.6 In-Reply-To: <1263508051-7868-23-git-send-email-gregkh@suse.de> References: <20100114222551.GA7839@suse.de> <1263508051-7868-1-git-send-email-gregkh@suse.de> <1263508051-7868-2-git-send-email-gregkh@suse.de> <1263508051-7868-3-git-send-email-gregkh@suse.de> <1263508051-7868-4-git-send-email-gregkh@suse.de> <1263508051-7868-5-git-send-email-gregkh@suse.de> <1263508051-7868-6-git-send-email-gregkh@suse.de> <1263508051-7868-7-git-send-email-gregkh@suse.de> <1263508051-7868-8-git-send-email-gregkh@suse.de> <1263508051-7868-9-git-send-email-gregkh@suse.de> <1263508051-7868-10-git-send-email-gregkh@suse.de> <1263508051-7868-11-git-send-email-gregkh@suse.de> <1263508051-7868-12-git-send-email-gregkh@suse.de> <1263508051-7868-13-git-send-email-gregkh@suse.de> <1263508051-7868-14-git-send-email-gregkh@suse.de> <1263508051-7868-15-git-send-email-gregkh@suse.de> <1263508051-7868-16-git-send-email-gregkh@suse.de> <1263508051-7868-17-git-send-email-gregkh@suse.de> <1263508051-7868-18-git-send-email-gregkh@suse.de> <1263508051-7868-19-git-send-email-gregkh@suse.de> <1263508051-7868-20-git-send-email-gregkh@suse.de> <1263508051-7868-21-git-send-email-gregkh@suse.de> <1263508051-7868-22-git-send-email-gregkh@suse.de> <1263508051-7868-23-git-send-email-gregkh@suse.de> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Krzysztof Halasa commit 42d53b4ff7d61487d18274ebdf1f70c1aef6f122 upstream. There is no need to perform full BIDIR sync (copying the buffers in case of swiotlb and similar schemes) if we know that the owner (CPU or device) hasn't altered the data. Addresses the false-positive reported at http://bugzilla.kernel.org/show_bug.cgi?id=14169 Signed-off-by: Krzysztof Halasa Cc: David Miller Cc: Joerg Roedel Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- lib/dma-debug.c | 7 +++---- 1 files changed, 3 insertions(+), 4 deletions(-) diff --git a/lib/dma-debug.c b/lib/dma-debug.c index 5a77c7c..084e879 100644 --- a/lib/dma-debug.c +++ b/lib/dma-debug.c @@ -913,6 +913,9 @@ static void check_sync(struct device *dev, ref->size); } + if (entry->direction == DMA_BIDIRECTIONAL) + goto out; + if (ref->direction != entry->direction) { err_printk(dev, entry, "DMA-API: device driver syncs " "DMA memory with different direction " @@ -923,9 +926,6 @@ static void check_sync(struct device *dev, dir2name[ref->direction]); } - if (entry->direction == DMA_BIDIRECTIONAL) - goto out; - if (to_cpu && !(entry->direction == DMA_FROM_DEVICE) && !(ref->direction == DMA_TO_DEVICE)) err_printk(dev, entry, "DMA-API: device driver syncs " @@ -948,7 +948,6 @@ static void check_sync(struct device *dev, out: put_hash_bucket(bucket, &flags); - } void debug_dma_map_page(struct device *dev, struct page *page, size_t offset, -- 1.6.6