blob: cf10fa880d2087df93d6a4e1d657c92932447e6a (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
|
From: Matt Porter <mporter@ti.com>
Date: Thu, 20 Sep 2012 08:55:41 -0400
Subject: [PATCH] mmc: omap_hsmmc: limit max_segs with the EDMA DMAC
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.
TODO: this will be replaced once the DMA Engine API supports an
API to query the DMAC's segment size limit.
Signed-off-by: Matt Porter <mporter@ti.com>
---
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 f74141e..4fe62b0 100644
--- a/drivers/mmc/host/omap_hsmmc.c
+++ b/drivers/mmc/host/omap_hsmmc.c
@@ -1833,6 +1833,16 @@ 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;
|
