Re: [gentoo-user] Re: Issues with AMD_IOMMU

Worse, ideally you wouldn't be using SWIOTLB but I don't know how to 
disable this without re-compiling the kernel.


On 05/21/2017 07:12 PM, Adam Carter wrote:
> <snip>
>
>>> [    0.991863] iommu: Adding device 0000:06:00.0 to group 12
>>> [    0.991982] iommu: Adding device 0000:07:04.0 to group 12
>>> [    1.063849] AMD-Vi: Found IOMMU at 0000:00:00.2 cap 0x40
>>> [    1.063962] AMD-Vi: Interrupt remapping enabled
>>> [    1.064145] AMD-Vi: Lazy IO/TLB flushing enabled
>>> [    1.065331] perf: AMD NB counters detected
> q
> I'm similar, but have a couple of extra entries. I've read a little bit
> about them, but so far am unable to determine if their existence indicates
> a better or worse kernel config.
>
> [    1.036309] AMD-Vi: Lazy IO/TLB flushing enabled
> [    1.036419] PCI-DMA: Using software bounce buffering for IO (SWIOTLB)
> [    1.036529] software IO TLB [mem 0xba61a000-0xbe61a000] (64MB) mapped at
> [ffffa3b87a61a000-ffffa3b87e619fff]
> [    1.036744] perf: AMD NB counters detected
>
> And the Linux AGP Driver ( in-kernel ) is working now.
>> Now this is showing properly with lspci :
>> 00:00.2 IOMMU: Advanced Micro Devices, Inc. [AMD/ATI] RD890S/RD990 I/O
>> Memory Management Unit (IOMMU)
>>
> Same.
>