diff mbox series

media: coda: request to skip kernel mapping for decoded buffers

Message ID 20191024103249.680-1-p.zabel@pengutronix.de (mailing list archive)
State New, archived
Headers show
Series media: coda: request to skip kernel mapping for decoded buffers | expand

Commit Message

Philipp Zabel Oct. 24, 2019, 10:32 a.m. UTC 
From: Lucas Stach <l.stach@pengutronix.de>

The kernel driver never touches the decoded buffers with the CPU.
All accesses are either done by hardware DMA masters or userspace
mapping the buffers. This means we don't need a kernel virtual
address mapping for those buffers at all. As those buffers are
usually quite large, we can save a good deal of kernel vmalloc
space by requesting to not have a kernel mapping set up for them.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
---
 drivers/media/platform/coda/coda-common.c | 1 +
 1 file changed, 1 insertion(+)
diff mbox series

Patch

diff --git a/drivers/media/platform/coda/coda-common.c b/drivers/media/platform/coda/coda-common.c
index 834f11fe9dc2..287dc1692286 100644
--- a/drivers/media/platform/coda/coda-common.c
+++ b/drivers/media/platform/coda/coda-common.c
@@ -2387,6 +2387,7 @@  int coda_decoder_queue_init(void *priv, struct vb2_queue *src_vq,
 
 	dst_vq->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
 	dst_vq->io_modes = VB2_DMABUF | VB2_MMAP;
+	dst_vq->dma_attrs = DMA_ATTR_NO_KERNEL_MAPPING;
 	dst_vq->mem_ops = &vb2_dma_contig_memops;
 
 	return coda_queue_init(priv, dst_vq);