On Fri, Aug 15, 2025 at 08:24:57AM +0000, Tian, Kevin wrote:

quoted

From: Nicolin Chen <redacted>
Sent: Tuesday, August 12, 2025 6:59 AM

The iommu_deferred_attach() is a runtime asynchronous function called by
iommu-dma function, which could race against other attach functions if it
accesses something in the dev->iommu_group.

Is there a real racing scenario being observed or more theoretical?

I think the commit message should explain the actual reason this is
being done, which AFAICT because the new lockdeps added in following
patches will fail on this path otherwise.

Jason