On 2018-05-01 01:15 AM, Dave Airlie wrote:
Yes, I fixed the original false positive messages myself with the swiotlb maintainer and I was CCed in fixing the recent fallout from Chris changes as well.
So do we have a good summary of where this at now?
I'm getting reports on 4.16.4 still displaying these, what hammer do I need to hit things with to get 4.16.x+1 to not do this?
Is there still outstanding issues upstream.
There are, https://patchwork.freedesktop.org/patch/219765/ should hopefully fix the last of it.
[...] I've no idea if the swiotlb things people report are the false positive, or some new thing.
The issues I've seen reported with 4.16 are false positives from TTM's perspective, which uses DMA_ATTR_NO_WARN to suppress these warnings, due to multiple regressions introduced by commit 0176adb004065d6815a8e67946752df4cd947c5b "swiotlb: refactor coherent buffer allocation" in 4.16-rc1.