[alsa-devel] [PATCH] ASoC: omap-pcm: Lower the dma coherent mask to 32bits

[Peter Ujfalusi]

Hi Russell,

On 12/09/2013 07:03 PM, Russell King - ARM Linux wrote:
> Yes, that's a good idea.  Revised version of the patch.  Peter, can you
> retest please, thanks.

With this patch PandaES and BeagleXM works fine on top of today's mainline.

Thank you Russell and Takashi!

Tested-by: Peter Ujfalusi <peter.ujfalusi at ti.com>

> diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
> index f6b6bfa88ecf..86c564e52ea7 100644
> --- a/arch/arm/mm/dma-mapping.c
> +++ b/arch/arm/mm/dma-mapping.c
> @@ -158,6 +158,44 @@ struct dma_map_ops arm_coherent_dma_ops = {
>  };
>  EXPORT_SYMBOL(arm_coherent_dma_ops);
>  
> +static int __dma_supported(struct device *dev, u64 mask, bool warn)
> +{
> +	unsigned long max_dma_pfn;
> +
> +	/*
> +	 * If the mask allows for more memory than we can address,
> +	 * and we actually have that much memory, then we must
> +	 * indicate that DMA to this device is not supported.
> +	 */
> +	if (sizeof(mask) != sizeof(dma_addr_t) &&
> +	    mask > (dma_addr_t)~0 &&
> +	    dma_to_pfn(dev, ~0) < max_pfn) {
> +		if (warn) {
> +			dev_warn(dev, "Coherent DMA mask %#llx is larger than dma_addr_t allows\n",
> +				 mask);
> +			dev_warn(dev, "Driver did not use or check the return value from dma_set_coherent_mask()?\n");
> +		}
> +		return 0;
> +	}
> +
> +	max_dma_pfn = min(max_pfn, arm_dma_pfn_limit);
> +
> +	/*
> +	 * Translate the device's DMA mask to a PFN limit.  This
> +	 * PFN number includes the page which we can DMA to.
> +	 */
> +	if (dma_to_pfn(dev, mask) < max_dma_pfn) {
> +		if (warn)
> +			dev_warn(dev, "Coherent DMA mask %#llx (pfn %#lx-%#lx) covers a smaller range of system memory than the DMA zone pfn 0x0-%#lx\n",
> +				 mask,
> +				 dma_to_pfn(dev, 0), dma_to_pfn(dev, mask) + 1,
> +				 max_dma_pfn + 1);
> +		return 0;
> +	}
> +
> +	return 1;
> +}
> +
>  static u64 get_coherent_dma_mask(struct device *dev)
>  {
>  	u64 mask = (u64)DMA_BIT_MASK(32);
> @@ -176,34 +214,8 @@ static u64 get_coherent_dma_mask(struct device *dev)
>  			return 0;
>  		}
>  
> -		max_dma_pfn = min(max_pfn, arm_dma_pfn_limit);
> -
> -		/*
> -		 * If the mask allows for more memory than we can address,
> -		 * and we actually have that much memory, then fail the
> -		 * allocation.
> -		 */
> -		if (sizeof(mask) != sizeof(dma_addr_t) &&
> -		    mask > (dma_addr_t)~0 &&
> -		    dma_to_pfn(dev, ~0) > max_dma_pfn) {
> -			dev_warn(dev, "Coherent DMA mask %#llx is larger than dma_addr_t allows\n",
> -				 mask);
> -			dev_warn(dev, "Driver did not use or check the return value from dma_set_coherent_mask()?\n");
> -			return 0;
> -		}
> -
> -		/*
> -		 * Now check that the mask, when translated to a PFN,
> -		 * fits within the allowable addresses which we can
> -		 * allocate.
> -		 */
> -		if (dma_to_pfn(dev, mask) < max_dma_pfn) {
> -			dev_warn(dev, "Coherent DMA mask %#llx (pfn %#lx-%#lx) covers a smaller range of system memory than the DMA zone pfn 0x0-%#lx\n",
> -				 mask,
> -				 dma_to_pfn(dev, 0), dma_to_pfn(dev, mask) + 1,
> -				 arm_dma_pfn_limit + 1);
> +		if (!__dma_supported(dev, mask, true))
>  			return 0;
> -		}
>  	}
>  
>  	return mask;
> @@ -1032,28 +1044,7 @@ void arm_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
>   */
>  int dma_supported(struct device *dev, u64 mask)
>  {
> -	unsigned long limit;
> -
> -	/*
> -	 * If the mask allows for more memory than we can address,
> -	 * and we actually have that much memory, then we must
> -	 * indicate that DMA to this device is not supported.
> -	 */
> -	if (sizeof(mask) != sizeof(dma_addr_t) &&
> -	    mask > (dma_addr_t)~0 &&
> -	    dma_to_pfn(dev, ~0) > arm_dma_pfn_limit)
> -		return 0;
> -
> -	/*
> -	 * Translate the device's DMA mask to a PFN limit.  This
> -	 * PFN number includes the page which we can DMA to.
> -	 */
> -	limit = dma_to_pfn(dev, mask);
> -
> -	if (limit < arm_dma_pfn_limit)
> -		return 0;
> -
> -	return 1;
> +	return __dma_supported(dev, mask, false);
>  }
>  EXPORT_SYMBOL(dma_supported);
>  
> 


-- 
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