* [PATCH v2] media: vb2: Fix vb2_dc_prepare do not correct sync data to device
2015-09-24 9:02 [PATCH v2] media: vb2: Fix vb2_dc_prepare do not correct sync data to device Tiffany Lin
@ 2015-09-24 9:02 ` Tiffany Lin
0 siblings, 0 replies; 2+ messages in thread
From: Tiffany Lin @ 2015-09-24 9:02 UTC (permalink / raw)
To: linux-arm-kernel
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,
--
1.8.1.1.dirty
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