[PATCH] of: Set the DMA mask to 64 bits on ARM LPAE systems

Laura Abbott lauraa at codeaurora.org
Wed Apr 24 10:50:49 EST 2013


By default on ARM systems, the coherent DMA mask (lowest
address) is set to ~0 or 0xFFFFFFFFFFFFFFFF. Currently,
of_platform_device_create_pdata sets the coherent DMA mask to
32 bits. This prevents coherent dma allocations from working by default
without clients setting the DMA mask. Rather than make every client
on an LPAE system set the mask, set the mask to a 64 bit value on
ARM LPAE systems.

Signed-off-by: Laura Abbott <lauraa at codeaurora.org>
---
 drivers/of/platform.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index 0970505..18b69c1 100644
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -214,7 +214,11 @@ struct platform_device *of_platform_device_create_pdata(
 #if defined(CONFIG_MICROBLAZE)
 	dev->archdata.dma_mask = 0xffffffffUL;
 #endif
+#ifdef CONFIG_ARM_LPAE
+	dev->dev.coherent_dma_mask = DMA_BIT_MASK(64);
+#else
 	dev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
+#endif
 	dev->dev.bus = &platform_bus_type;
 	dev->dev.platform_data = platform_data;
 
-- 
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