[PATCH v2] media: vb2: Fix vb2_dc_prepare do not correct sync data to device
From: Tiffany Lin <tiffany.lin@mediatek.com>
Date: 2015-09-24 09:02:46
Change in v2: Apply same fix to videobuf2-dma-sg
[PATCH v2] media: vb2: Fix vb2_dc_prepare do not correct sync data to device
STALE3964d
2 messages, 1 author, 2015-09-24 · open the first message on its own page
[PATCH v2] media: vb2: Fix vb2_dc_prepare do not correct sync data to device
From: Tiffany Lin <tiffany.lin@mediatek.com>
Date: 2015-09-24 09:02:51
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 <tiffany.lin@mediatek.com> --- 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,
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1.8.1.1.dirty