RE: swiotlb/caamjr regression (Was: [GIT PULL] (swiotlb) stable/for-linus-5.12)

+ Bumyong who is the original author of the patch. 

Hi Dominique,

Thanks!
(a bit late, but added Chanho Park in Cc...)

I can confirm it also works for our caam problem, as Horia said.

I've also come to term with the use of swiotlb_align_offset() through
testing, or rather many devices seem to have a 0 mask so it will almost
always be cancelled out, so if it works for Jianxiong then it's probably
good enough and I'll just assume that's how the orig_addr has been
designed...

I think it's missing a couple of checks like the one Linus had in his
patch, and would be comfortable with something like the attached patch (in
practice for me exactly the same as the original patch, except I've added
two checks: offsets smaller than orig addr offset are refused as well as
offsets bigger than the mapping size)

I'm sorry Jianxiong but would you be willing to take the time to test
again just to make sure there were no such offsets in your case?


If we're good with that I'll send it as an official v2 keeping Chanho's
from, unless he wants to.

Sure. No problem. But, the patch was already stacked on Konrad's tree
and linux-next as well.

https://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb.git/commit/?h=devel/for-linus-5.14&id=33d1641f38f0c327bc3e5c21de585c77a6512bc6 

Best Regards, 
Chanho Park