Re: [PATCH] drm/exynos: Add check for IOMMU while passing physically continous memory flag

[Sylwester Nawrocki <s.nawrocki@samsung.com>]

Hi Vikas,

On 08/02/2013 12:10 PM, Vikas Sajjan wrote:
> yeah, we could not allocate CMA region for FIMD, because the function
> dma_declare_contiguous() needs "dev" as the first argument and we have
> access to "dev" node only if it is NON-DT way of probing like the way
> it is done in arch/arm/mach-davinci/devices-da8xx.c
> But now, since the probing is through DT way, there is NO way ( Let me
> know if something is newly added ) to call dma_declare_contiguous()
> and reserve CMA region .

See this patch series [1]. We have have been using this kind of bindings
for assigning physically contiguous memory regions to the Exynos 
multimedia devices, instead of what's currently in mainline where same
physical addresses are repeated in dts for various boards without much
thought. And where custom device specific parsing code is required at 
arch side.

$ git grep mfc\-[lr] arch/arm/boot/dts

arch/arm/boot/dts/exynos4210-origen.dts:     samsung,mfc-r = <0x43000000 0x800000>;
arch/arm/boot/dts/exynos4210-origen.dts:     samsung,mfc-l = <0x51000000 0x800000>;
arch/arm/boot/dts/exynos4210-smdkv310.dts:   samsung,mfc-r = <0x43000000 0x800000>;
arch/arm/boot/dts/exynos4210-smdkv310.dts:   samsung,mfc-l = <0x51000000 0x800000>;
arch/arm/boot/dts/exynos4412-origen.dts:     samsung,mfc-r = <0x43000000 0x800000>;
arch/arm/boot/dts/exynos4412-origen.dts:     samsung,mfc-l = <0x51000000 0x800000>;
arch/arm/boot/dts/exynos4412-smdk4412.dts:   samsung,mfc-r = <0x43000000 0x800000>;
arch/arm/boot/dts/exynos4412-smdk4412.dts:   samsung,mfc-l = <0x51000000 0x800000>;
arch/arm/boot/dts/exynos5250-arndale.dts:    samsung,mfc-r = <0x43000000 0x800000>;
arch/arm/boot/dts/exynos5250-arndale.dts:    samsung,mfc-l = <0x51000000 0x800000>;
arch/arm/boot/dts/exynos5250-smdk5250.dts:   samsung,mfc-r = <0x43000000 0x800000>;
arch/arm/boot/dts/exynos5250-smdk5250.dts:   samsung,mfc-l = <0x51000000 0x800000>;


[1] http://www.spinics.net/lists/arm-kernel/msg263130.html

Regards,
Sylwester