On Wed, 27 Jun 2012 16:44:14 +0200
Thierry Reding [off-list ref] wrote:

quoted

I think that "coherent_pool" can be used only when the amount of
contiguous memory is short in your system. Otherwise even unnecessary.

Could you explain a bit more why you want carveout size on per-board basis?

In the ideal case I would want to not have a carveout size at all.
However there may be situations where you need to make sure some driver
can allocate a given amount of memory. Having to specify this using a
kernel command-line parameter is cumbersome because it may require
changes to the bootloader or whatever. So if you know that a particular
board always needs 128 MiB of carveout, then it makes sense to specify
it on a per-board basis.

Hm...I could understand somewhat;) but DT can also specify "bootargs"
in dts file, which can support per-board-wide spec too, like the above
sum of carveout needed from all drivers. I just want to avoid
introducing a new parameter additionaly if we can make use of the
existing mechanism.