[REGRESSION, BISECTED] DMA mask issue on ReadyNAS 102 w/ 3.13.0-rc3

[Arnaud Ebalard]

Hi Russell,

Russell King - ARM Linux <linux at arm.linux.org.uk> writes:

> On Sun, Dec 08, 2013 at 12:02:45AM +0100, Arnaud Ebalard wrote:
>> 3.13.0-rc2 worked just fine so I decided to git-bisect the issue and
>> ended up on 11a5aa32562e (ARM: dma-mapping: check DMA mask against
>> available memory).
>> 
>> If it has already been reported and fixed, sorry for the noise.
>
> Please try this patch, thanks:
>
> diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
> index f6b6bfa88ecf..c143a7bb681b 100644
> --- a/arch/arm/mm/dma-mapping.c
> +++ b/arch/arm/mm/dma-mapping.c
> @@ -185,7 +185,7 @@ static u64 get_coherent_dma_mask(struct device *dev)
>  		 */
>  		if (sizeof(mask) != sizeof(dma_addr_t) &&
>  		    mask > (dma_addr_t)~0 &&
> -		    dma_to_pfn(dev, ~0) > max_dma_pfn) {
> +		    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");
> @@ -1041,7 +1041,7 @@ int dma_supported(struct device *dev, u64 mask)
>  	 */
>  	if (sizeof(mask) != sizeof(dma_addr_t) &&
>  	    mask > (dma_addr_t)~0 &&
> -	    dma_to_pfn(dev, ~0) > arm_dma_pfn_limit)
> +	    dma_to_pfn(dev, ~0) < min(max_pfn, arm_dma_pfn_limit))
>  		return 0;
>  
>  	/*
>

With that applied, 3.13.0-rc3 boots again on my RN102 w/o any error.

Cheers,

a+