On Tue, Jan 27, 2015 at 3:00 PM, Murali Karicheri <m-karicheri2@xxxxxx> 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@xxxxxxxxxx>
> Cc: Grant Likely <grant.likely@xxxxxxxxxx>
> Cc: Rob Herring <robh+dt@xxxxxxxxxx>
> Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> Cc: Will Deacon <will.deacon@xxxxxxx>
> Cc: Russell King <linux@xxxxxxxxxxxxxxxx>
> Cc: Arnd Bergmann <arnd@xxxxxxxx>
> Cc: Suravee Suthikulpanit <Suravee.Suthikulpanit@xxxxxxx>
>
> Signed-off-by: Murali Karicheri <m-karicheri2@xxxxxx>
> ---
> drivers/of/device.c | 9 ++++++++-
> 1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/of/device.c b/drivers/of/device.c
> index 2de320d..17504f4 100644
> --- a/drivers/of/device.c
> +++ b/drivers/of/device.c
> @@ -105,12 +105,19 @@ 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;
This is fine since coherent_dma_mask will always be 4G - 1 in this case.
> } else {
> offset = PFN_DOWN(paddr - dma_addr);
> dev_dbg(dev, "dma_pfn_offset(%#08lx)\n", offset);
> }
>
> + if (is_power_of_2(size + 1))
> + size = size + 1;
> + else if (!is_power_of_2(size)) {
> + dev_err(dev, "invalid size\n");
> + return;
I think this is too restrictive. I think checking bit 0 is 1 is enough
to tell the size is a mask.
I would like it to be a WARN if detected and just add 1.
Rob
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