Re: [PATCH v2 1/2] USB: dwc3-exynos: Add support for device tree

[kishon <kishon@ti.com>]

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:
>> This patch adds support to parse probe data for
>> dwc3-exynos driver using device tree.
>>
>> Signed-off-by: Vivek Gautam <gautam.vivek@samsung.com>
>> ---
>>   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