ACK: [PATCH][Unstable][SRU Disco] iommu/arm-smmu-v3: Don't disable SMMU in kdump kernel

Seth Forshee seth.forshee at
Wed May 29 17:53:28 UTC 2019

On Mon, May 13, 2019 at 12:28:23PM -0600, dann frazier wrote:
> From: Will Deacon <will.deacon at>
> BugLink:
> Disabling the SMMU when probing from within a kdump kernel so that all
> incoming transactions are terminated can prevent the core of the crashed
> kernel from being transferred off the machine if all I/O devices are
> behind the SMMU.
> Instead, continue to probe the SMMU after it is disabled so that we can
> reinitialise it entirely and re-attach the DMA masters as they are reset.
> Since the kdump kernel may not have drivers for all of the active DMA
> masters, we suppress fault reporting to avoid spamming the console and
> swamping the IRQ threads.
> Reported-by: "Leizhen (ThunderTown)" <thunder.leizhen at>
> Tested-by: "Leizhen (ThunderTown)" <thunder.leizhen at>
> Tested-by: Bhupesh Sharma <bhsharma at>
> Signed-off-by: Will Deacon <will.deacon at>
> (cherry picked from commit 3f54c447df34ff9efac7809a4a80fd3208efc619)
> Signed-off-by: dann frazier <dann.frazier at>

Acked-by: Seth Forshee <seth.forshee at>

This is already present in unstable/master. Thanks!

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