Re: [PATCH v6 3/7] of: fix size when dma-range is not used

[Catalin Marinas <catalin.marinas@arm.com>]

On Thu, Feb 05, 2015 at 09:52:55PM +0000, Murali Karicheri wrote:
> Fix the dma-range size when the DT attribute is missing. i.e  set size to
> dev->coherent_dma_mask + 1 instead of dev->coherent_dma_mask. Also add
> code to check invalid values of size configured in DT and log error.
> 
> Cc: Joerg Roedel <joro@8bytes.org>
> Cc: Grant Likely <grant.likely@linaro.org>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: Bjorn Helgaas <bhelgaas@google.com>
> Cc: Will Deacon <will.deacon@arm.com>
> Cc: Russell King <linux@arm.linux.org.uk>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
> 
> Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
> ---
>  drivers/of/device.c |   17 ++++++++++++++++-
>  1 file changed, 16 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/of/device.c b/drivers/of/device.c
> index 2de320d..314c8a9 100644
> --- a/drivers/of/device.c
> +++ b/drivers/of/device.c
> @@ -105,9 +105,24 @@ void of_dma_configure(struct device *dev, struct device_node *np)
>  	ret = of_dma_get_range(np, &dma_addr, &paddr, &size);
>  	if (ret < 0) {
>  		dma_addr = offset = 0;
> -		size = dev->coherent_dma_mask;
> +		size = dev->coherent_dma_mask + 1;
>  	} else {
>  		offset = PFN_DOWN(paddr - dma_addr);
> +
> +		/*
> +		 * Add a work around to treat the size as mask + 1 in case
> +		 * it is defined in DT as a mask.
> +		 */
> +		if (size & 1) {
> +			dev_warn(dev, "Invalid size 0x%llx for dma-range\n",
> +				 size);
> +			size = size + 1;
> +		}
> +
> +		if (!size) {
> +			dev_err(dev, "Adjusted size 0x%llx invalid\n", size);
> +			return;
> +		}

Would it make sense to set coherent_dma_mask to 0 here to make this more
noticeable? It can be done together with the mask calculation from size.

-- 
Catalin