Re: [PATCH] firmware: arm_ffa: Unmap RxTx buffers on device shutdown

[Sudeep Holla <sudeep.holla@kernel.org>]

On Wed, Aug 26, 2026 at 06:47:11PM -0400, Maxi Saparov wrote:
> Apologies, I failed to spot Carol's earlier patch for the same
> problem before sending this:
> 
>   https://lore.kernel.org/all/20260818224404.3694580-1-csoto@nvidia.com/
> 
> Please disregard my patch in favor of that one. It covers more than
> mine does.
> 
> Some corroborating data from our side, in case it helps that patch
> along. We hit this on NVIDIA GB200 systems in production diagnostics:
> after a kexec from a kernel with FF-A active, the next kernel's
> FFA_RXTX_MAP is denied and the driver fails to probe until a full
> system reset. I can also confirm Carol's observation that unmapping
> the buffers alone is not enough. The notification bitmap is retained
> by the SPMC in the same way, so the cleanup has to cover both.
> 
> Happy to provide Tested-by on the next revision of Carol's patch.
> 

I had replied to Carol with reference to [1]. I prefer that approach, see if
that helps.

-- 
Regards,
Sudeep


[1] https://lore.kernel.org/all/20260729-nostalgic-accurate-raccoon-ab7d7e@sudeepholla/