Re: OMAPFB: CMA allocation failures

From: Tomi Valkeinen
Date: Wed Oct 30 2013 - 08:20:21 EST

On 2013-10-29 14:47, ÐÐÐÐÐÐ ÐÐÐÐÑÑÐÐ wrote:

> However, back to omapfb - my understanding is that the way it uses CMA (in its current form) is
> prone to allocation failures way beyond acceptable.
> Tomi, what do you think about adding module parameters to allow pre-allocating framebuffer memory
> from CMA during boot? Or re-implement VRAM allocator to use CMA? As a good side-effect
> OMAPFB_GET_VRAM_INFO will no longer return fake values.

I really dislike the idea of adding the omap vram allocator back. Then
again, if the CMA doesn't work, something has to be done.

Pre-allocating is possible, but that won't work if there's any need to
re-allocating the framebuffers. Except if the omapfb would retain and
manage the pre-allocated buffers, but that would just be more or less
the old vram allocator again.

So, as I see it, the best option would be to have the standard dma_alloc
functions get the memory for omapfb from a private pool, which is not
used for anything else.

I wonder if that's possible already? It sounds quite trivial to me.


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