[PATCH v2] of/device: Update dma_range_map only when dev has valid dma-ranges

[Yong Wu]

The commit e0d072782c73 ("dma-mapping: introduce DMA range map,
supplanting dma_pfn_offset") always update dma_range_map even though it was
already set, like in the sunxi_mbus driver. the issue is reported at [1].
This patch avoid this(Updating it only when dev has valid dma-ranges).

Meanwhile, dma_range_map contains the devices' dma_ranges information,
This patch moves dma_range_map before of_iommu_configure. The iommu
driver may need to know the dma_address requirements of its iommu
consumer devices.

[1] https://lore.kernel.org/linux-arm-kernel/5c7946f3-b56e-da00-a750-be097c7ceb32@arm.com/

CC: Rob Herring <robh+dt at kernel.org>
CC: Frank Rowand <frowand.list at gmail.com>
Fixes: e0d072782c73 ("dma-mapping: introduce DMA range map, supplanting dma_pfn_offset"),
Suggested-by: Robin Murphy <robin.murphy at arm.com>
Signed-off-by: Yong Wu <yong.wu at mediatek.com>
Signed-off-by: Paul Kocialkowski <paul.kocialkowski at bootlin.com>
Reviewed-by: Rob Herring <robh at kernel.org>
---
 drivers/of/device.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/of/device.c b/drivers/of/device.c
index aedfaaafd3e7..1122daa8e273 100644
--- a/drivers/of/device.c
+++ b/drivers/of/device.c
@@ -162,9 +162,11 @@ int of_dma_configure_id(struct device *dev, struct device_node *np,
 	mask = DMA_BIT_MASK(ilog2(end) + 1);
 	dev->coherent_dma_mask &= mask;
 	*dev->dma_mask &= mask;
-	/* ...but only set bus limit if we found valid dma-ranges earlier */
-	if (!ret)
+	/* ...but only set bus limit and range map if we found valid dma-ranges earlier */
+	if (!ret) {
 		dev->bus_dma_limit = end;
+		dev->dma_range_map = map;
+	}
 
 	coherent = of_dma_is_coherent(np);
 	dev_dbg(dev, "device is%sdma coherent\n",
@@ -172,6 +174,9 @@ int of_dma_configure_id(struct device *dev, struct device_node *np,
 
 	iommu = of_iommu_configure(dev, np, id);
 	if (PTR_ERR(iommu) == -EPROBE_DEFER) {
+		/* Don't touch range map if it wasn't set from a valid dma-ranges */
+		if (!ret)
+			dev->dma_range_map = NULL;
 		kfree(map);
 		return -EPROBE_DEFER;
 	}
@@ -181,7 +186,6 @@ int of_dma_configure_id(struct device *dev, struct device_node *np,
 
 	arch_setup_dma_ops(dev, dma_start, size, iommu, coherent);
 
-	dev->dma_range_map = map;
 	return 0;
 }
 EXPORT_SYMBOL_GPL(of_dma_configure_id);
-- 
2.18.0