From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751167AbdAQDF2 (ORCPT ); Mon, 16 Jan 2017 22:05:28 -0500 Received: from mailgw02.mediatek.com ([210.61.82.184]:58307 "EHLO mailgw02.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1750826AbdAQDEy (ORCPT ); Mon, 16 Jan 2017 22:04:54 -0500 From: Miles Chen To: Andrew Morton CC: , , Miles Chen Subject: [PATCH] dma-debug: add comment for failed to check map error Date: Tue, 17 Jan 2017 11:04:49 +0800 Message-ID: <1484622289-22085-1-git-send-email-miles.chen@mediatek.com> X-Mailer: git-send-email 1.9.1 MIME-Version: 1.0 Content-Type: text/plain X-MTK: N Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add comment for failed to check map error to help driver developers. Signed-off-by: Miles Chen --- lib/dma-debug.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/lib/dma-debug.c b/lib/dma-debug.c index 8971370..60c57ec 100644 --- a/lib/dma-debug.c +++ b/lib/dma-debug.c @@ -1155,6 +1155,11 @@ static void check_unmap(struct dma_debug_entry *ref) dir2name[ref->direction]); } + /* + * Drivers should use dma_mapping_error() to check the returned + * addresses of dma_map_single() and dma_map_page(). + * If not, print this warning message. See Documentation/DMA-API.txt. + */ if (entry->map_err_type == MAP_ERR_NOT_CHECKED) { err_printk(ref->dev, entry, "DMA-API: device driver failed to check map error" -- 1.9.1