Re: [PATCH rc v2 0/5] iommu/arm-smmu-v3: Fix device crash on kdump kernel
From: Jason Gunthorpe
Date: Fri Apr 17 2026 - 08:00:27 EST
On Fri, Apr 17, 2026 at 07:48:46AM +0000, Tian, Kevin wrote:
> is there any report on such systems? It might be informational to include
> a link to the report so it's clear that this series fixes real issues instead of
> a preparation for coming systems...
Yeah, we have an internal report and this was confirmed to fix it.
> btw the DMA is allowed after the previous kernel is hung til the point
> where smmu driver blocks it. In cases where in-fly DMAs are considered
> dangerous to kdump, this series just make it worse instead of creating
> a new issue. While for majority other failures not related to DMAs,
> unblocking then increases the chance of success...
Right, exactly.
If DMA's are splattering over the kdump carve out memory its is
probably dead no matter what.
Jason