Re: [PATCH 2/2] remoteproc: sysmon: Wait for shutdown-ack/ind on sysmon shutdown

[Sibi Sankar]

Hi Bjorn,
Thanks for the review!

On 2018-12-06 12:46, Bjorn Andersson wrote:
> On Tue 20 Nov 13:02 PST 2018, Sibi Sankar wrote:
>
> > After sending a sysmon shutdown request to the SSCTL service on the
> > subsystem, wait for the service to send shutdown-ack interrupt or
> > an indication message back.
>
> So we get a reply immediate on the shutdown request, and then some time
> later we get either an indication or an interrupt to state that it's
> actually complete?

Yes, after the immediate qmi result response
we get either indication/shutdown-ack interrupt
or both. This would indicate that the graceful
shutdown is complete and wouldn't further require
a qcom_q6v5_request_stop.

> > Signed-off-by: Sibi Sankar <sibis@xxxxxxxxxxxxxx>
> > ---
> >  drivers/remoteproc/qcom_sysmon.c | 59 
> > +++++++++++++++++++++++++++++++-
> >  1 file changed, 58 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/remoteproc/qcom_sysmon.c 
> > b/drivers/remoteproc/qcom_sysmon.c
> [..]
> > @@ -283,6 +311,14 @@ static void ssctl_request_shutdown(struct 
> > qcom_sysmon *sysmon)
> >  		dev_err(sysmon->dev, "shutdown request failed\n");
> >  	else
> >  		dev_dbg(sysmon->dev, "shutdown request completed\n");
> > +
> > +	if (sysmon->shutdown_irq > 0) {
> > +		ret = wait_for_completion_timeout(&sysmon->shutdown_comp,
> > +						  msecs_to_jiffies(5000));
>
> 5 * HZ

sure

> > +		if (!ret)
> > +			dev_err(sysmon->dev,
> > +				"timeout waiting for shutdown ack\n");
> > +	}
> >  }
> [..]
> > @@ -453,14 +499,25 @@ struct qcom_sysmon 
> > *qcom_add_sysmon_subdev(struct rproc *rproc,
> >
> >  	sysmon->dev = rproc->dev.parent;
> >  	sysmon->rproc = rproc;
> > +	pdev = container_of(sysmon->dev, struct platform_device, dev);
> >
> >  	sysmon->name = name;
> >  	sysmon->ssctl_instance = ssctl_instance;
> >
> >  	init_completion(&sysmon->comp);
> > +	init_completion(&sysmon->shutdown_comp);
> >  	mutex_init(&sysmon->lock);
> >
> > -	ret = qmi_handle_init(&sysmon->qmi, SSCTL_MAX_MSG_LEN, &ssctl_ops, 
> > NULL);
> > +	sysmon->shutdown_irq = platform_get_irq_byname(pdev, 
> > "shutdown-ack");
>
> Use of_irq_get_byname() on sysmon->dev instead of relying on the fact
> that the remoteproc driver is a platform_device.
>
> Also, check and handle the return value - because an EPROBE_DEFER here
> will be turned into a -EINVAL by devm_request_threaded_irq().

handling -EPROBE_DEFER would require changing the prototype
of add_sysmon_subdev, so can it come as a separate patch?

> > +	ret = devm_request_threaded_irq(sysmon->dev, sysmon->shutdown_irq,
> > +					NULL, sysmon_shutdown_interrupt,
> > +					IRQF_TRIGGER_RISING | IRQF_ONESHOT,
> > +					"q6v5 shutdown-ack", sysmon);
> > +	if (ret)
> > +		dev_err(sysmon->dev, "failed to acquire shutdown-ack IRQ\n");
>
> In the event that sysmon->shutdown_irq is != -ENODATA, you should fail
> here.

don't we want this to be a optional property? meaning we
shouldn't fail for -EINVAL..

> > +
> > +	ret = qmi_handle_init(&sysmon->qmi, SSCTL_MAX_MSG_LEN, &ssctl_ops,
> > +			      qmi_indication_handler);
>
> Regards,
> Bjorn

--
-- Sibi Sankar --
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