dmaengine: omap-dma: Fix dynamic lch_map allocation

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>
Cc: stable@vger.kernel.org   # v4.9
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>

diff --git a/drivers/dma/omap-dma.c b/drivers/dma/omap-dma.c
index ac68666cd3f4e99cd3bc2f4ae346f5e78cd218ce..4ad101a47e0a1bcabbc034bfab67dfa3a3b83ec4 100644 (file)
--- a/drivers/dma/omap-dma.c
+++ b/drivers/dma/omap-dma.c
@@ -1452,6 +1452,7 @@ 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)
@@ -1494,20 +1495,31 @@ 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;