On Tue, Nov 07, 2017 at 07:48:42AM -0800, Tony Lindgren wrote:

Hi,

* Joonsoo Kim [off-list ref] [171107 05:30]:

quoted

Could you test follwing updated branch?

https://github.com/JoonsooKim/linux/tree/cma-debug4-next-20180901

It has three relevant commits on top and enables CMA memory use.

Okie dokie.

quoted

"arm/dma: remove i-cache flush"

Your branch at the above commit is not booting on n900.

quoted

"arm/dma: flush i-cache and d-cache separately"

Not booting at this commit either.

quoted

"arm/dma: call flush_cache_all() and don't do outer cache operation"

Not booting at this commit either.

Earlier commit f14f3479c0d7 ("arm/dma: re-enable to remap the CMA
area and flush cache before remapping") in you branch boots.

Then the following commit d6512d6d0171 ("Revert "arm/mm: disable
atomic_pool"") won't boot.

Also your tree at commit 6d0525cef962 ("arm/dma: remove i-cache
flush") with only commit d6512d6d0171 ("Revert "arm/mm: disable
atomic_pool"") reverted boots on n900.

Thanks a lot!

So it seems the issue is currently at the atomic_pool_init()
related code?

Yes, your test showed it although I can't find any clue in
atomic_pool_init().

Could you test updated branch?

https://github.com/JoonsooKim/linux/tree/cma-debug4-next-20180901

There are two relevant commits.

arm/dma: stop dma allocation before __dma_alloc_remap()
arm/dma: disable atomic pool after dma allocation

atomic pool initialization will be done partially to check
exact point of failure. These are brain-dead commits however I have no
idea what's going on here until now. :/

Thanks.