If device has no DMA max_seg_size set, we assume that there is no limit
and it is safe to force it to use DMA_BIT_MASK(32) as max_seg_size to
let DMA-mapping API always create contiguous mappings in DMA address
space. This is essential for all devices, which use dma-contig
videobuf2 memory allocator.
Signed-off-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
---
drivers/media/v4l2-core/videobuf2-dma-contig.c | 17 +++++++++++++++++
1 file changed, 17 insertions(+)
diff --git a/drivers/media/v4l2-core/videobuf2-dma-contig.c b/drivers/media/v4l2-core/videobuf2-dma-contig.c
index 644dec73d220..9d7c1814b0f3 100644
--- a/drivers/media/v4l2-core/videobuf2-dma-contig.c
+++ b/drivers/media/v4l2-core/videobuf2-dma-contig.c
@@ -862,6 +862,23 @@ EXPORT_SYMBOL_GPL(vb2_dma_contig_memops);
void *vb2_dma_contig_init_ctx(struct device *dev)
{
struct vb2_dc_conf *conf;
+ int err;
+
+ /*
+ * if device has no max_seg_size set, we assume that there is no limit
+ * and force it to DMA_BIT_MASK(32) to always use contiguous mappings
+ * in DMA address space
+ */
+ if (!dev->dma_parms) {
+ dev->dma_parms = kzalloc(sizeof(*dev->dma_parms), GFP_KERNEL);
+ if (!dev->dma_parms)
+ return ERR_PTR(-ENOMEM);
+ }
+ if (dma_get_max_seg_size(dev) < DMA_BIT_MASK(32)) {
+ err = dma_set_max_seg_size(dev, DMA_BIT_MASK(32));
+ if (err)
+ return ERR_PTR(err);
+ }
conf = kzalloc(sizeof *conf, GFP_KERNEL);
if (!conf)
--
1.9.2
--
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