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Date:   Tue, 23 Jun 2020 13:38:30 -0600
From:   Mathieu Poirier <mathieu.poirier@linaro.org>
To:     Bjorn Andersson <bjorn.andersson@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: <20200623193830.GB1908098@xps15>
References: <20200601175139.22097-1-mathieu.poirier@linaro.org>
 <20200601175139.22097-6-mathieu.poirier@linaro.org>
 <20200622072502.GG149351@builder.lan>
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On Mon, Jun 22, 2020 at 12:25:02AM -0700, Bjorn Andersson wrote:
> 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.
> 

Sure thing.

> 
> 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
> >