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Date:   Mon, 22 Jun 2020 00:18:04 -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 3/9] remoteproc: Introducing function rproc_attach()
Message-ID: <20200622071804.GE149351@builder.lan>
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 <20200622070727.GD149351@builder.lan>
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On Mon 22 Jun 00:07 PDT 2020, Bjorn Andersson wrote:

> On Mon 01 Jun 10:51 PDT 2020, Mathieu Poirier wrote:
> 
> > Introducing function rproc_attach() to enact the same actions as
> > rproc_start(), but without the steps related to the handling of
> > a firmware image.  That way we can properly deal with scenarios
> > where the remoteproc core needs to attach with a remote processsor
> > that has been booted by another entity.
> > 
> > Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
> > ---
> >  drivers/remoteproc/remoteproc_core.c | 42 ++++++++++++++++++++++++++++
> >  1 file changed, 42 insertions(+)
> > 
> > diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
> > index 9f04c30c4aaf..0b323f6b554b 100644
> > --- a/drivers/remoteproc/remoteproc_core.c
> > +++ b/drivers/remoteproc/remoteproc_core.c
> > @@ -1370,6 +1370,48 @@ static int rproc_start(struct rproc *rproc, const struct firmware *fw)
> >  	return ret;
> >  }
> >  
> > +static int __maybe_unused rproc_attach(struct rproc *rproc)
> > +{
> > +	struct device *dev = &rproc->dev;
> > +	int ret;
> > +
> 
> For the case where we're going DETACHED -> RUNNING - > OFFLINE we
> need to consider the pm_runtime (and prepare/unprepare) state of the
> device as well...
> 

Missed that you do indeed pm_runtime_get() in the calling function, so I
think we're good on that part. Still need how to actually implement
that (and the prepare/unprepare), in particular if we're moving into
detaching a remoteproc.

> 
> Apart from that I think this looks good.
> 

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

Regards,
Bjorn

> Regards,
> Bjorn
> 
> > +	ret = rproc_prepare_subdevices(rproc);
> > +	if (ret) {
> > +		dev_err(dev, "failed to prepare subdevices for %s: %d\n",
> > +			rproc->name, ret);
> > +		goto out;
> > +	}
> > +
> > +	/* Attach to the remote processor */
> > +	ret = rproc_attach_device(rproc);
> > +	if (ret) {
> > +		dev_err(dev, "can't attach to rproc %s: %d\n",
> > +			rproc->name, ret);
> > +		goto unprepare_subdevices;
> > +	}
> > +
> > +	/* Start any subdevices for the remote processor */
> > +	ret = rproc_start_subdevices(rproc);
> > +	if (ret) {
> > +		dev_err(dev, "failed to probe subdevices for %s: %d\n",
> > +			rproc->name, ret);
> > +		goto stop_rproc;
> > +	}
> > +
> > +	rproc->state = RPROC_RUNNING;
> > +
> > +	dev_info(dev, "remote processor %s is now attached\n", rproc->name);
> > +
> > +	return 0;
> > +
> > +stop_rproc:
> > +	rproc->ops->stop(rproc);
> > +unprepare_subdevices:
> > +	rproc_unprepare_subdevices(rproc);
> > +out:
> > +	return ret;
> > +}
> > +
> >  /*
> >   * take a firmware and boot a remote processor with it.
> >   */
> > -- 
> > 2.20.1
> >