Hi Tomi,

patch 
http://lists.infradead.org/pipermail/linux-arm-kernel/2012-November/131269.html 
modifies
omapfb driver to use DMA API to allocate framebuffer memory instead of 
preallocating VRAM.

With this patch I see a lot of:

Jan  1 06:33:27 Nokia-N900 kernel: [ 2054.879577] cma: 
dma_alloc_from_contiguous(cma c05f5844, count 192, align 8)
Jan  1 06:33:27 Nokia-N900 kernel: [ 2054.914215] cma: 
dma_alloc_from_contiguous(): memory range at c07df000 is busy, retrying
Jan  1 06:33:27 Nokia-N900 kernel: [ 2054.933502] cma: 
dma_alloc_from_contiguous(): memory range at c07e1000 is busy, retrying
Jan  1 06:33:27 Nokia-N900 kernel: [ 2054.940032] cma: 
dma_alloc_from_contiguous(): memory range at c07e3000 is busy, retrying
Jan  1 06:33:27 Nokia-N900 kernel: [ 2054.966644] cma: 
dma_alloc_from_contiguous(): memory range at c07e5000 is busy, retrying
Jan  1 06:33:27 Nokia-N900 kernel: [ 2054.976867] cma: 
dma_alloc_from_contiguous(): memory range at c07e7000 is busy, retrying
Jan  1 06:33:27 Nokia-N900 kernel: [ 2055.038055] cma: 
dma_alloc_from_contiguous(): memory range at c07e9000 is busy, retrying
Jan  1 06:33:27 Nokia-N900 kernel: [ 2055.038116] cma: 
dma_alloc_from_contiguous(): returned   (null)
Jan  1 06:33:27 Nokia-N900 kernel: [ 2055.038146] omapfb omapfb: failed to 
allocate framebuffer

errors while trying to play a video on N900 with Maemo 5 (Fremantle) on top of 
linux-3.12rc1.
It is deffinitely the CMA that fails to allocate the memory most of the times, 
but I wonder
how reliable CMA is to be used in omapfb. I even reserved 64MB for CMA, but 
that made no
difference. If CMA is disabled, the memory allocation still fails as obviously 
it is highly
unlikely there will be such a big chunk of continuous free memory on RAM 
limited device like
N900. 

One obvious solution is to just revert the removal of VRAM memory allocator, 
but that would
mean I'll have to maintain a separate tree with all the implications that 
brings.

What would you advise on how to deal with the issue?

Regards,
Ivo
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to