The EDMA DMAC has a hardware limitation that prevents supporting
scatter gather lists with any number of segments. Since the EDMA
DMA Engine driver sets the maximum segments to 16, we do the
same.
Note: this can be removed once the DMA Engine API supports an
API to query the DMAC's segment limitations.
Signed-off-by: Matt Porter <mporter@xxxxxx>
---
drivers/mmc/host/omap_hsmmc.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c
index c82d0ab..61b54ee 100644
--- a/drivers/mmc/host/omap_hsmmc.c
+++ b/drivers/mmc/host/omap_hsmmc.c
@@ -1885,6 +1885,16 @@ static int __devinit omap_hsmmc_probe(struct platform_device *pdev)
* as we want. */
mmc->max_segs = 1024;
+ /* Eventually we should get our max_segs limitation for EDMA by
+ * querying the dmaengine API */
+ if (pdev->dev.of_node) {
+ struct device_node *parent = pdev->dev.of_node->parent;
+ struct device_node *node;
+ node = of_find_node_by_name(parent, "edma");
+ if (node)
+ mmc->max_segs = 16;
+ }
+
mmc->max_blk_size = 512; /* Block Length at max can be 1024 */
mmc->max_blk_count = 0xFFFF; /* No. of Blocks is 16 bits */
mmc->max_req_size = mmc->max_blk_size * mmc->max_blk_count;
--
1.7.9.5
--
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