Date:   Fri, 3 Feb 2023 14:36:26 +0000
From:   Cristian Marussi <cristian.marussi@arm.com>
To:     Etienne Carriere <etienne.carriere@linaro.org>
Cc:     linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        Jens Wiklander <jens.wiklander@linaro.org>,
        Sumit Garg <sumit.garg@linaro.org>,
        Sudeep Holla <sudeep.holla@arm.com>
Subject: Re: [PATCH 2/2] firmware: arm_scmi: optee: use optee system
 invocation
Message-ID: <Y90b6kxAtbookjty@pluto>
References: <20230130094157.1082712-1-etienne.carriere@linaro.org>
 <20230130094157.1082712-2-etienne.carriere@linaro.org>
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On Mon, Jan 30, 2023 at 10:41:57AM +0100, Etienne Carriere wrote:
> Changes SCMI optee transport to enable sys_service capability of
> its tee context to leverage provisioned system resources in OP-TEE
> preventing possible deadlock.
> 
> Such deadlock could happen when many Linux clients invoke OP-TEE are
> are all suspended waiting for an OP-TEE RPC request access an SCMI
> resource through the SCMI OP-TEE PTA service.
> 
> Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>
> ---
>  drivers/firmware/arm_scmi/optee.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/firmware/arm_scmi/optee.c b/drivers/firmware/arm_scmi/optee.c
> index 2a7aeab40e54..91840345e946 100644
> --- a/drivers/firmware/arm_scmi/optee.c
> +++ b/drivers/firmware/arm_scmi/optee.c
> @@ -559,6 +559,9 @@ static int scmi_optee_service_probe(struct device *dev)
>  	if (IS_ERR(tee_ctx))
>  		return -ENODEV;
>  
> +	/* SCMI agent can used TEE system service resources */
> +	tee_ctx->sys_service = true;
> +
>  	agent = devm_kzalloc(dev, sizeof(*agent), GFP_KERNEL);
>  	if (!agent) {
>  		ret = -ENOMEM;

LGTM.

I suppose you'll sync-up with Sudeep for how to queue this whole series.

Thanks,
Cristian