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Date:   Wed, 22 Jun 2022 11:25:29 -0600
From:   Mathieu Poirier <mathieu.poirier@linaro.org>
To:     "Peng Fan (OSS)" <peng.fan@oss.nxp.com>
Cc:     bjorn.andersson@linaro.org, linux-remoteproc@vger.kernel.org,
        linux-kernel@vger.kernel.org, Peng Fan <peng.fan@nxp.com>
Subject: Re: [PATCH V5 2/2] remoteproc: support attach recovery after rproc
 crash
Message-ID: <20220622172529.GC1606016@p14s>
References: <20220615032048.465486-1-peng.fan@oss.nxp.com>
 <20220615032048.465486-3-peng.fan@oss.nxp.com>
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On Wed, Jun 15, 2022 at 11:20:48AM +0800, Peng Fan (OSS) wrote:
> From: Peng Fan <peng.fan@nxp.com>
> 
> Current logic only support main processor to stop/start the remote
> processor after rproc crash. However to SoC, such as i.MX8QM/QXP, the
> remote processor could do attach recovery after crash and trigger watchdog
> reboot. It does not need main processor to load image, or stop/start M4
> core.
> 
> Introduce two functions: rproc_attach_recovery, rproc_firmware_recovery
> for the two cases. Firmware recovery is as before, let main processor to
> help recovery, while attach recovery is recover itself withou help.
> To attach recovery, we only do detach and attach.
> 
> Signed-off-by: Peng Fan <peng.fan@nxp.com>
> ---
>  drivers/remoteproc/remoteproc_core.c | 64 +++++++++++++++++++---------
>  1 file changed, 45 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
> index 02a04ab34a23..1c1c90176aff 100644
> --- a/drivers/remoteproc/remoteproc_core.c
> +++ b/drivers/remoteproc/remoteproc_core.c
> @@ -1883,6 +1883,47 @@ static int __rproc_detach(struct rproc *rproc)
>  	return 0;
>  }
>  
> +static int rproc_attach_recovery(struct rproc *rproc)
> +{
> +	int ret;
> +
> +	mutex_unlock(&rproc->lock);
> +	ret = __rproc_detach(rproc);
> +	mutex_lock(&rproc->lock);
> +	if (ret)
> +		return ret;
> +
> +	return __rproc_attach(rproc);
> +}
> +
> +static int rproc_firmware_recovery(struct rproc *rproc)

s/rproc_firmware_recovery/rproc_boot_recovery

> +{
> +	const struct firmware *firmware_p;
> +	struct device *dev = &rproc->dev;
> +	int ret;
> +
> +	ret = rproc_stop(rproc, true);
> +	if (ret)
> +		return ret;
> +
> +	/* generate coredump */
> +	rproc->ops->coredump(rproc);
> +
> +	/* load firmware */
> +	ret = request_firmware(&firmware_p, rproc->firmware, dev);
> +	if (ret < 0) {
> +		dev_err(dev, "request_firmware failed: %d\n", ret);
> +		return ret;
> +	}
> +
> +	/* boot the remote processor up again */
> +	ret = rproc_start(rproc, firmware_p);
> +
> +	release_firmware(firmware_p);
> +
> +	return ret;
> +}
> +
>  /**
>   * rproc_trigger_recovery() - recover a remoteproc
>   * @rproc: the remote processor
> @@ -1897,7 +1938,6 @@ static int __rproc_detach(struct rproc *rproc)
>   */
>  int rproc_trigger_recovery(struct rproc *rproc)
>  {
> -	const struct firmware *firmware_p;
>  	struct device *dev = &rproc->dev;
>  	int ret;
>  
> @@ -1911,24 +1951,10 @@ int rproc_trigger_recovery(struct rproc *rproc)
>  
>  	dev_err(dev, "recovering %s\n", rproc->name);
>  
> -	ret = rproc_stop(rproc, true);
> -	if (ret)
> -		goto unlock_mutex;
> -
> -	/* generate coredump */
> -	rproc->ops->coredump(rproc);
> -
> -	/* load firmware */
> -	ret = request_firmware(&firmware_p, rproc->firmware, dev);
> -	if (ret < 0) {
> -		dev_err(dev, "request_firmware failed: %d\n", ret);
> -		goto unlock_mutex;
> -	}
> -
> -	/* boot the remote processor up again */
> -	ret = rproc_start(rproc, firmware_p);
> -
> -	release_firmware(firmware_p);
> +	if (rproc_has_feature(rproc, RPROC_FEAT_ATTACH_ON_RECOVERY))
> +		ret = rproc_attach_recovery(rproc);
> +	else
> +		ret = rproc_firmware_recovery(rproc);

This patch contains a serious flaw related to locking that should have been
obvious when it was put together.  Please go back and carefully review the code you are submitting.  

I will not consider another revision of this set until July 15th.

Thanks,
Mathieu

>  
>  unlock_mutex:
>  	mutex_unlock(&rproc->lock);
> -- 
> 2.25.1
>