Hi,

On Tuesday 16 October 2012 03:23 PM, Felipe Balbi wrote:

On Tue, Oct 16, 2012 at 02:15:56PM +0530, Vivek Gautam wrote:

quoted

This patch adds support to parse probe data for
dwc3-exynos driver using device tree.

Signed-off-by: Vivek Gautam <redacted>
---
  drivers/usb/dwc3/dwc3-exynos.c |   20 ++++++++++++++++++++
  1 files changed, 20 insertions(+), 0 deletions(-)

diff --git a/drivers/usb/dwc3/dwc3-exynos.c b/drivers/usb/dwc3/dwc3-exynos.c
index ca65978..d11ef49 100644
--- a/drivers/usb/dwc3/dwc3-exynos.c
+++ b/drivers/usb/dwc3/dwc3-exynos.c

@@ -21,6 +21,7 @@
  #include <linux/clk.h>
  #include <linux/usb/otg.h>
  #include <linux/usb/nop-usb-xceiv.h>
+#include <linux/of.h>

  #include "core.h"

@@ -87,6 +88,8 @@ err1:
  	return ret;
  }

+static u64 dwc3_exynos_dma_mask = DMA_BIT_MASK(32);
+
  static int __devinit dwc3_exynos_probe(struct platform_device *pdev)
  {
  	struct dwc3_exynos_data	*pdata = pdev->dev.platform_data;

@@ -103,6 +106,14 @@ static int __devinit dwc3_exynos_probe(struct platform_device *pdev)
  		goto err0;
  	}

+	/*
+	 * Right now device-tree probed devices don't get dma_mask set.
+	 * Since shared usb code relies on it, set it here for now.
+	 * Once we move to full device tree support this will vanish off.
+	 */
+	if (!pdev->dev.dma_mask)
+		pdev->dev.dma_mask = &dwc3_exynos_dma_mask;

says who ?

$ git grep -e dma_mask drivers/of/
drivers/of/platform.c:  dev->dev.dma_mask = &dev->archdata.dma_mask;
drivers/of/platform.c:  dev->archdata.dma_mask = 0xffffffffUL;
drivers/of/platform.c:  dev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
drivers/of/platform.c:  dev->dev.coherent_dma_mask = ~0;
drivers/of/platform.c:  dev->dma_mask = ~0;

-ECONFUSED

dma_mask is set under some ifdef except for "dev->dma_mask = ~0;". 
However I agree with you for coherent_dma_mask case.

Thanks
Kishon