From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752863AbbIXJCv (ORCPT ); Thu, 24 Sep 2015 05:02:51 -0400 Received: from mailgw02.mediatek.com ([210.61.82.184]:33394 "EHLO mailgw02.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1752221AbbIXJCr (ORCPT ); Thu, 24 Sep 2015 05:02:47 -0400 X-Listener-Flag: 11101 From: Tiffany Lin To: Sakari Ailus , Hans Verkuil , Robin Murphy , Daniel Kurtz , Pawel Osciak , Marek Szyprowski , Kyungmin Park CC: Mauro Carvalho Chehab , Matthias Brugger , , , , , Tiffany Lin Subject: [PATCH v2] media: vb2: Fix vb2_dc_prepare do not correct sync data to device Date: Thu, 24 Sep 2015 17:02:36 +0800 Message-ID: <1443085356-1010-2-git-send-email-tiffany.lin@mediatek.com> X-Mailer: git-send-email 1.8.1.1.dirty In-Reply-To: <1443085356-1010-1-git-send-email-tiffany.lin@mediatek.com> References: <1443085356-1010-1-git-send-email-tiffany.lin@mediatek.com> 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 vb2_dc_prepare use the number of SG entries dma_map_sg_attrs return. But in dma_sync_sg_for_device, it use lengths of each SG entries before dma_map_sg_attrs. dma_map_sg_attrs will concatenate SGs until dma length > dma seg bundary. sgt->nents will less than sgt->orig_nents. Using SG entries after dma_map_sg_attrs in vb2_dc_prepare will make some SGs are not sync to device. After add DMA_ATTR_SKIP_CPU_SYNC in vb2_dc_get_userptr to remove sync data to device twice. Device randomly get incorrect data because some SGs are not sync to device. Change to use number of SG entries before dma_map_sg_attrs in vb2_dc_prepare to prevent this issue. Signed-off-by: Tiffany Lin --- drivers/media/v4l2-core/videobuf2-dma-contig.c | 4 ++-- drivers/media/v4l2-core/videobuf2-dma-sg.c | 5 ++--- 2 files changed, 4 insertions(+), 5 deletions(-) diff --git a/drivers/media/v4l2-core/videobuf2-dma-contig.c b/drivers/media/v4l2-core/videobuf2-dma-contig.c index 2397ceb..c5d00bd 100644 --- a/drivers/media/v4l2-core/videobuf2-dma-contig.c +++ b/drivers/media/v4l2-core/videobuf2-dma-contig.c @@ -100,7 +100,7 @@ static void vb2_dc_prepare(void *buf_priv) if (!sgt || buf->db_attach) return; - dma_sync_sg_for_device(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir); + dma_sync_sg_for_device(buf->dev, sgt->sgl, sgt->orig_nents, buf->dma_dir); } static void vb2_dc_finish(void *buf_priv) @@ -112,7 +112,7 @@ static void vb2_dc_finish(void *buf_priv) if (!sgt || buf->db_attach) return; - dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir); + dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->orig_nents, buf->dma_dir); } /*********************************************/ diff --git a/drivers/media/v4l2-core/videobuf2-dma-sg.c b/drivers/media/v4l2-core/videobuf2-dma-sg.c index be7bd65..a09f7fd 100644 --- a/drivers/media/v4l2-core/videobuf2-dma-sg.c +++ b/drivers/media/v4l2-core/videobuf2-dma-sg.c @@ -1,4 +1,3 @@ -/* * videobuf2-dma-sg.c - dma scatter/gather memory allocator for videobuf2 * * Copyright (C) 2010 Samsung Electronics @@ -210,7 +209,7 @@ static void vb2_dma_sg_prepare(void *buf_priv) if (buf->db_attach) return; - dma_sync_sg_for_device(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir); + dma_sync_sg_for_device(buf->dev, sgt->sgl, sgt->orig_nents, buf->dma_dir); } static void vb2_dma_sg_finish(void *buf_priv) @@ -222,7 +221,7 @@ static void vb2_dma_sg_finish(void *buf_priv) if (buf->db_attach) return; - dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir); + dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->orig_nents, buf->dma_dir); } static void *vb2_dma_sg_get_userptr(void *alloc_ctx, unsigned long vaddr, -- 1.8.1.1.dirty