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Date:   Fri, 21 Jul 2023 19:43:56 -0700
From:   Bjorn Andersson <andersson@kernel.org>
To:     Cristian Marussi <cristian.marussi@arm.com>
Cc:     linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        sudeep.holla@arm.com, james.quinlan@broadcom.com,
        f.fainelli@gmail.com, vincent.guittot@linaro.org, peng.fan@nxp.com,
        quic_nkela@quicinc.com
Subject: Re: [PATCH] firmware: arm_scmi: Fix chan_free cleanup on SMC
Message-ID: <rr26mp6bx4lu667qufvxjewo3fxg5c6hvhmstngliwhzbkbes4@owpr7vauvzwg>
References: <20230719173533.2739319-1-cristian.marussi@arm.com>
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On Wed, Jul 19, 2023 at 06:35:33PM +0100, Cristian Marussi wrote:
> SCMI transport based on SMC can optionally use an additional IRQ to signal
> message completion; the associated ISR is currently allocated using devres
> but the core SCMI stack, on shutdown, will call .chan_free() well before
> any managed cleanup is invoked by devres and, as a consequence, the arrival
> of a late reply to an in-flight pending transaction could still trigger the
> ISR well after the SCMI core has cleaned up the channels, with unpleasant
> results.
> 
> Inhibit further message processing on the IRQ path by explicitly freeing
> the IRQ inside .chan_free() callback itself.
> 
> Fixes: dd820ee21d5e ("firmware: arm_scmi: Augment SMC/HVC to allow optional interrupt")
> Reported-by: Bjorn Andersson <andersson@kernel.org>
> Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
> ---

Reviewed-by: Bjorn Andersson <andersson@kernel.org>

Regards,
Bjorn