Re: [PATCH 1/2] ARM: omapfb: add coherent dma memory support

[Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com>]

On 30.12.2013 15:19, Tomi Valkeinen wrote:
> The omapfb driver uses dma_alloc to reserve memory for the framebuffers.
> However, on some use cases, even when CMA is in use, it's quite probable
> that omapfb fails to allocate the fb, either due to not enough free dma
> memory, fragmented dma memory, or CMA failing to make enough contiguous
> space.
>
> This patch adds a kernel cmdline parameter 'omapfb_vram' which can be
> used to give the size of a memory area reserved exclusively for omapfb,
> and optionally a physical address where the memory area is reserved.
>
> The memory area is reserved with memblock, and assigned to omapfb with
> dma_declare_coherent_memory. The dma_alloc function will first try to
> allocate the fb from the coherent memory area, and if that fails, it'll
> use the normal method of allocation.
>
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
> Cc: Ivaylo Dimitrov <freemangordon@abv.bg>
> ---
>   arch/arm/mach-omap2/common.c |  1 +
>   arch/arm/mach-omap2/common.h |  2 ++
>   arch/arm/mach-omap2/fb.c     | 77 +++++++++++++++++++++++++++++++++++++++++++-
>   3 files changed, 79 insertions(+), 1 deletion(-)
>

Tested on Nokia N900 with Maemo5 and linux 3.13-rc6