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authorSergey Senozhatsky <sergey.senozhatsky@gmail.com>2020-09-11 05:07:58 +0200
committerMauro Carvalho Chehab <mchehab+huawei@kernel.org>2020-09-14 15:28:06 +0200
commit129134e5415d46f38b9978b3809af94ed649b57d (patch)
tree2024ff46ccc7024e47a7f7e66f201dbf6f3ee068 /drivers/media/common/videobuf2/videobuf2-dma-sg.c
parent288eceb0858323d66bff03cf386630a797b248ad (diff)
downloadlinux-129134e5415d46f38b9978b3809af94ed649b57d.tar.bz2
media: media/v4l2: remove V4L2_FLAG_MEMORY_NON_CONSISTENT flag
The patch partially reverts some of the UAPI bits of the buffer cache management hints. Namely, the queue consistency (memory coherency) user-space hint because, as it turned out, the kernel implementation of this feature was misusing DMA_ATTR_NON_CONSISTENT. The patch reverts both kernel and user space parts: removes the DMA consistency attr functions, rolls back changes to v4l2_requestbuffers, v4l2_create_buffers structures and corresponding UAPI functions (plus compat32 layer) and cleans up the documentation. [hverkuil: fixed a few typos in the commit log] [hverkuil: fixed vb2_core_reqbufs call in drivers/media/dvb-core/dvb_vb2.c] [mchehab: fixed a typo in the commit log: revers->reverts] Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Diffstat (limited to 'drivers/media/common/videobuf2/videobuf2-dma-sg.c')
-rw-r--r--drivers/media/common/videobuf2/videobuf2-dma-sg.c3
1 files changed, 1 insertions, 2 deletions
diff --git a/drivers/media/common/videobuf2/videobuf2-dma-sg.c b/drivers/media/common/videobuf2/videobuf2-dma-sg.c
index 0a40e00f0d7e..a86fce5d8ea8 100644
--- a/drivers/media/common/videobuf2/videobuf2-dma-sg.c
+++ b/drivers/media/common/videobuf2/videobuf2-dma-sg.c
@@ -123,8 +123,7 @@ static void *vb2_dma_sg_alloc(struct device *dev, unsigned long dma_attrs,
/*
* NOTE: dma-sg allocates memory using the page allocator directly, so
* there is no memory consistency guarantee, hence dma-sg ignores DMA
- * attributes passed from the upper layer. That means that
- * V4L2_FLAG_MEMORY_NON_CONSISTENT has no effect on dma-sg buffers.
+ * attributes passed from the upper layer.
*/
buf->pages = kvmalloc_array(buf->num_pages, sizeof(struct page *),
GFP_KERNEL | __GFP_ZERO);