Re: [PATCH iwl-net 2/2] idpf: reset the function on shutdown

[Tian Xun Ng <luckilystar08@gmail.com>]

On 9/18/2026, Tantilov, Emil S wrote:
> This alone would not be enough, you need to make sure the reset handling
> does not trigger in the driver. Sashiko is also marking it:
> you will have to set IDPF_REMOVE_IN_PROG, though I am not sure if that
> alone would be sufficient.

You are right, and so is the review bot. I missed it because our hardware
takes the PF path.

On the VF path idpf_vf_trigger_reset() sends VIRTCHNL2_OP_RESET_VF unless
IDPF_REMOVE_IN_PROG is set, and idpf_shutdown() calls
idpf_deinit_dflt_mbx() immediately after the trigger, which frees the ASQ
while that message is still outstanding. That is an enqueue-then-free of
DMA memory, and on a system with the IOMMU translating it is exactly the
class of fault this series is trying to remove. On the PF path
idpf_trigger_reset() only writes PFGEN_CTRL, which is why our testing
never hit it.

I will drop this patch from v2 rather than paper over it with a flag.
It was never load bearing: the stray writes are stopped by patch 1, and
this one only restored parity with idpf_remove(). If it turns out to be
worth having, it belongs in its own series with the VF path handled
properly.

Thanks for catching it.