[PATCH] drm/amdgpu: use ttm pool first

[Christian König]

Am 24.01.2018 um 11:32 schrieb Chunming Zhou:
> On 2018年01月24日 17:49, Christian König wrote:
>> [SNIP]
>> Nope, as I wrote that won't work. You must improve the detection if 
>> we need coherent or not coherent allocation.
> But how to differentiate coherent or not coherent allocation? check if 
> max io address of system memory under 40bits pcie address space? Do 
> you know how to get the max io address of system memory?

Well that is a good question, which nobody had an answer for so far (and 
a couple of people already looked into it).

We could start by checking if max_pfn is <= the 40bits limit or if IOMMU 
is enabled instead of SWIOTLB.

Regards,
Christian.