Re: [PATCH 2/3] omap3: change ISP's IOMMU da_start address

[Sakari Ailus <sakari.ailus@maxwell.research.nokia.com>]

David Cohen wrote:
> ISP doesn't consider 0x0 as a valid address, so it should explicitly
> exclude first page from allowed 'da' range.
> 
> Signed-off-by: David Cohen <dacohen@gmail.com>
> ---
>  arch/arm/mach-omap2/omap-iommu.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/arch/arm/mach-omap2/omap-iommu.c b/arch/arm/mach-omap2/omap-iommu.c
> index 3fc5dc7..3bea489 100644
> --- a/arch/arm/mach-omap2/omap-iommu.c
> +++ b/arch/arm/mach-omap2/omap-iommu.c
> @@ -33,7 +33,7 @@ static struct iommu_device omap3_devices[] = {
>  			.name = "isp",
>  			.nr_tlb_entries = 8,
>  			.clk_name = "cam_ick",
> -			.da_start = 0x0,
> +			.da_start = 0x1000,

The NULL address is still valid for the MMU. Can the IOVMF_DA_ANON
mapping be specified by the API to be always non-NULL?

This way it would be possible to combine IOVMF_DA_FIXED and
IOVMF_DA_ANON mappings in the same IOMMU while still being able to rely
that IOVMF_DA_ANON mappings would always be non-NULL.

Regards,

-- 
Sakari Ailus
sakari.ailus@maxwell.research.nokia.com