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Patch "dmaengine: omap-dma: Fix dynamic lch_map allocation" has been added to the 4.9-stable tree

PATCH [email protected] 1 participant 1 message Jan 17, 2017

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This is a note to let you know that I've just added the patch titled

dmaengine: omap-dma: Fix dynamic lch_map allocation

to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
dmaengine-omap-dma-fix-dynamic-lch_map-allocation.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

Quoted 1 line

From 836c3ce2566fb8c1754f8d7c9534cad9bc8a6879 Mon Sep 17 00:00:00 2001

From: Peter Ujfalusi <[email protected]>
Date: Mon, 2 Jan 2017 12:07:37 +0200
Subject: dmaengine: omap-dma: Fix dynamic lch_map allocation

From: Peter Ujfalusi <[email protected]>

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 <[email protected]>
Signed-off-by Peter Ujfalusi <[email protected]>
Tested-by Aaro Koskinen <[email protected]>
Signed-off-by Vinod Koul <[email protected]>
Signed-off-by Greg Kroah-Hartman <[email protected]>
---
 drivers/dma/omap-dma.c |   30 +++++++++++++++++++++---------
 1 file changed, 21 insertions(+), 9 deletions(-)
drivers/dma/omap-dma.c +21 -9
@@ -1339,6 +1339,7 @@ static int omap_dma_probe(struct platfor
 	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 platfor
 	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;

Patches currently in stable-queue which might be from [email protected] are

queue-4.9/dmaengine-omap-dma-fix-dynamic-lch_map-allocation.patch