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 <redacted>
Cc: Ivaylo Dimitrov <redacted>
---
  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