dmaengine: omap-dma: Fix dynamic lch_map allocation

commit 836c3ce2566fb8c1754f8d7c9534cad9bc8a6879 upstream.

The original patch did not done what it was supposed to be doing and even
worst it broke legacy boot (OMAP1).

The lch_map size should be the number of available logical channels in sDMA
and the od->dma_requests should store the number of available DMA request
lines usable in sDMA.

In legacy mode we do not have a way to get the DMA request count, in that
case we use OMAP_SDMA_REQUESTS (127), despite the fact that OMAP1510 have
only 31 DMA request line.

Fixes: 2d1a9a946fae ("dmaengine: omap-dma: Dynamically allocate memory for lch_map")
Reported-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Tested-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 21 insertions, 9 deletions

diff --git a/drivers/dma/omap-dma.c b/drivers/dma/omap-dma.c
index 7ca27d4b1c54..6b16ce390dce 100644
--- a/drivers/dma/omap-dma.c
+++ b/drivers/dma/omap-dma.c
@@ -1339,6 +1339,7 @@ static int omap_dma_probe(struct platform_device *pdev)
         struct omap_dmadev *od;
         struct resource *res;
         int rc, i, irq;
+        u32 lch_count;
 
         od = devm_kzalloc(&pdev->dev, sizeof(*od), GFP_KERNEL);
         if (!od)
@@ -1381,20 +1382,31 @@ static int omap_dma_probe(struct platform_device *pdev)
         spin_lock_init(&od->lock);
         spin_lock_init(&od->irq_lock);
 
-        if (!pdev->dev.of_node) {
-                od->dma_requests = od->plat->dma_attr->lch_count;
-                if (unlikely(!od->dma_requests))
-                        od->dma_requests = OMAP_SDMA_REQUESTS;
-        } else if (of_property_read_u32(pdev->dev.of_node, "dma-requests",
-                                        &od->dma_requests)) {
+        /* Number of DMA requests */
+        od->dma_requests = OMAP_SDMA_REQUESTS;
+        if (pdev->dev.of_node && of_property_read_u32(pdev->dev.of_node,
+                                                      "dma-requests",
+                                                      &od->dma_requests)) {
                 dev_info(&pdev->dev,
                          "Missing dma-requests property, using %u.\n",
                          OMAP_SDMA_REQUESTS);
-                od->dma_requests = OMAP_SDMA_REQUESTS;
         }
 
-        od->lch_map = devm_kcalloc(&pdev->dev, od->dma_requests,
-                                   sizeof(*od->lch_map), GFP_KERNEL);
+        /* Number of available logical channels */
+        if (!pdev->dev.of_node) {
+                lch_count = od->plat->dma_attr->lch_count;
+                if (unlikely(!lch_count))
+                        lch_count = OMAP_SDMA_CHANNELS;
+        } else if (of_property_read_u32(pdev->dev.of_node, "dma-channels",
+                                        &lch_count)) {
+                dev_info(&pdev->dev,
+                         "Missing dma-channels property, using %u.\n",
+                         OMAP_SDMA_CHANNELS);
+                lch_count = OMAP_SDMA_CHANNELS;
+        }
+
+        od->lch_map = devm_kcalloc(&pdev->dev, lch_count, sizeof(*od->lch_map),
+                                   GFP_KERNEL);
         if (!od->lch_map)
                 return -ENOMEM;