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authorMarek Szyprowski <m.szyprowski@samsung.com>2016-05-24 09:16:06 +0200
committerSylwester Nawrocki <s.nawrocki@samsung.com>2016-06-03 11:12:50 +0200
commit3f03396918962b2f8b888d02b23cd1e0c88bf5e5 (patch)
treede42cca354178aca1f9588536eee6e35dfd1c417 /include/media
parentc974c436eaf406225b7f4c5d27ae033a12667a38 (diff)
media: vb2-dma-contig: add helper for setting dma max seg size
Add a helper function for device drivers to set DMA's max_seg_size. Setting it to largest possible value lets DMA-mapping API always create contiguous mappings in DMA address space. This is essential for all devices, which use dma-contig videobuf2 memory allocator and shared buffers. Till now, the only case when vb2-dma-contig really 'worked' was a case where userspace provided USERPTR buffer, which was in fact mmaped contiguous buffer from the other v4l2/drm device. Also DMABUF made of contiguous buffer worked only when its exporter did not split it into several chunks in the scatter-list. Any other buffer failed, regardless of the arch/platform used and the presence of the IOMMU of the device bus. This patch provides interface to fix this issue. Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Diffstat (limited to 'include/media')
-rw-r--r--include/media/videobuf2-dma-contig.h2
1 files changed, 2 insertions, 0 deletions
diff --git a/include/media/videobuf2-dma-contig.h b/include/media/videobuf2-dma-contig.h
index 2087c9a68be3..f7dc8401817e 100644
--- a/include/media/videobuf2-dma-contig.h
+++ b/include/media/videobuf2-dma-contig.h
@@ -35,6 +35,8 @@ static inline void *vb2_dma_contig_init_ctx(struct device *dev)
}
void vb2_dma_contig_cleanup_ctx(void *alloc_ctx);
+int vb2_dma_contig_set_max_seg_size(struct device *dev, unsigned int size);
+void vb2_dma_contig_clear_max_seg_size(struct device *dev);
extern const struct vb2_mem_ops vb2_dma_contig_memops;