Subject: dma_alloc_coherent fails in framebuffer

From: [email-masked] (Tony Prisk)
Date: Sun, 14 Oct 2012 18:28:43 +1300

Up until 07 Oct, drivers/video/wm8505-fb.c was working fine, but on the
11 Oct when I did another pull from linus all of a sudden
dma_alloc_coherent is failing to allocate the framebuffer any longer.

I did a quick look back and found this:

ARM: add coherent dma ops

arch_is_coherent is problematic as it is a global symbol. This
doesn't work for multi-platform kernels or platforms which can support
per device coherent DMA.

This adds arm_coherent_dma_ops to be used for devices which connected
coherently (i.e. to the ACP port on Cortex-A9 or A15). The arm_dma_ops
are modified at boot when arch_is_coherent is true.

Signed-off-by: Rob Herring <[email-masked]>
Cc: Russell King <[email-masked]>
Cc: Marek Szyprowski <[email-masked]>
Signed-off-by: Marek Szyprowski <[email-masked]>

This is the only patch lately that I could find (not that I would claim
to be any good at finding things) that is related to the problem. Could
it have caused the allocations to fail?

Regards
Tony P