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Date:   Mon, 22 Jun 2020 00:25:02 -0700
From:   Bjorn Andersson <bjorn.andersson@linaro.org>
To:     Mathieu Poirier <mathieu.poirier@linaro.org>
Cc:     ohad@wizery.com, linux-remoteproc@vger.kernel.org,
        linux-kernel@vger.kernel.org, loic.pallardy@st.com,
        arnaud.pouliquen@st.com, s-anna@ti.com
Subject: Re: [PATCH v4 5/9] remoteproc: Introducing function rproc_validate()
Message-ID: <20200622072502.GG149351@builder.lan>
References: <20200601175139.22097-1-mathieu.poirier@linaro.org>
 <20200601175139.22097-6-mathieu.poirier@linaro.org>
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On Mon 01 Jun 10:51 PDT 2020, Mathieu Poirier wrote:

> Add a new function to assert the general health of the remote
> processor before handing it to the remoteproc core.
> 
> Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
> ---
>  drivers/remoteproc/remoteproc_core.c | 45 ++++++++++++++++++++++++++++
>  1 file changed, 45 insertions(+)
> 
> diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
> index c70fa0372d07..0be8343dd851 100644
> --- a/drivers/remoteproc/remoteproc_core.c
> +++ b/drivers/remoteproc/remoteproc_core.c
> @@ -2060,6 +2060,47 @@ struct rproc *rproc_get_by_phandle(phandle phandle)
>  #endif
>  EXPORT_SYMBOL(rproc_get_by_phandle);
>  
> +static int rproc_validate(struct rproc *rproc)
> +{
> +	/*
> +	 * When adding a remote processor, the state of the device
> +	 * can be offline or detached, nothing else.
> +	 */
> +	if (rproc->state != RPROC_OFFLINE &&
> +	    rproc->state != RPROC_DETACHED)
> +		goto inval;

I would prefer that you just return -EINVAL; directly.

Overall I think this would be better represented as a switch on
rproc->state though.


I think the logic is sound though.

Regards,
Bjorn

> +
> +	if (rproc->state == RPROC_OFFLINE) {
> +		/*
> +		 * An offline processor without a start()
> +		 * function makes no sense.
> +		 */
> +		if (!rproc->ops->start)
> +			goto inval;
> +	}
> +
> +	if (rproc->state == RPROC_DETACHED) {
> +		/*
> +		 * A remote processor in a detached state without an
> +		 * attach() function makes not sense.
> +		 */
> +		if (!rproc->ops->attach)
> +			goto inval;
> +		/*
> +		 * When attaching to a remote processor the device memory
> +		 * is already available and as such there is no need to have a
> +		 * cached table.
> +		 */
> +		if (rproc->cached_table)
> +			goto inval;
> +	}
> +
> +	return 0;
> +
> +inval:
> +	return -EINVAL;
> +}
> +
>  /**
>   * rproc_add() - register a remote processor
>   * @rproc: the remote processor handle to register
> @@ -2089,6 +2130,10 @@ int rproc_add(struct rproc *rproc)
>  	if (ret < 0)
>  		return ret;
>  
> +	ret = rproc_validate(rproc);
> +	if (ret < 0)
> +		return ret;
> +
>  	dev_info(dev, "%s is available\n", rproc->name);
>  
>  	/* create debugfs entries */
> -- 
> 2.20.1
>