Re: [PATCH] remoteproc: qcom: q6v5: Add interconnect path proxy vote

[Georgi Djakov]

On 8.03.22 0:42, Bjorn Andersson wrote:
> On Mon 07 Mar 10:35 PST 2022, Georgi Djakov wrote:
>
> > On 25.02.22 5:32, Bjorn Andersson wrote:
> > > Many remoteproc instances requires that Linux casts a proxy vote for an
> > > interconnect path during boot, until they can do it themselves. Add
> > > support for voting for a single path.
> > >
> > > As this is a shared problem between both PAS and MSS drivers, the path
> > > is acquired and votes casted from the common helper code.
> > >
> > > Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
> > > ---
> > >
> > > Sibi posted recently a patch to add interconnect votes from the modem driver,
> > > today I needed the same feature for one of the PAS remoteprocs. After
> > > essentially duplicating Sibi's patch I realized that it doesn't look too bad to
> > > put this in the common Q6V5 code.
> > >
> > > The main difference is that this would be messy if we need to support multiple
> > > paths, so we probably would have to push it out to the individual drivers at
> > > that point.
> > >
> > > Sibi's patch can be found here.
> > > https://lore.kernel.org/all/1644813252-12897-3-git-send-email-quic_sibis@xxxxxxxxxxx/
> > >
> > >
> > > This makes the implementation pick up one path, relevant DT bindings would
> > > still need to be updated in order be allowed to this in the DeviceTree files.
> > >
> > >    drivers/remoteproc/qcom_q6v5.c | 21 ++++++++++++++++++++-
> > >    drivers/remoteproc/qcom_q6v5.h |  3 +++
> > >    2 files changed, 23 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/remoteproc/qcom_q6v5.c b/drivers/remoteproc/qcom_q6v5.c
> > > index 442a388f8102..5280ec9b5449 100644
> > > --- a/drivers/remoteproc/qcom_q6v5.c
> > > +++ b/drivers/remoteproc/qcom_q6v5.c
> > > @@ -8,6 +8,7 @@
> > >     */
> > >    #include <linux/kernel.h>
> > >    #include <linux/platform_device.h>
> > > +#include <linux/interconnect.h>
> > >    #include <linux/interrupt.h>
> > >    #include <linux/module.h>
> > >    #include <linux/soc/qcom/qcom_aoss.h>
> > > @@ -51,9 +52,17 @@ int qcom_q6v5_prepare(struct qcom_q6v5 *q6v5)
> > >    {
> > >    	int ret;
> > > +	ret = icc_set_bw(q6v5->path, 0, UINT_MAX);
> > > +	if (ret < 0) {
> > > +		dev_err(q6v5->dev, "failed to set bandwidth request\n");
> > > +		return ret;
> > > +	}
> > > +
> > >    	ret = q6v5_load_state_toggle(q6v5, true);
> > > -	if (ret)
> > > +	if (ret) {
> > > +		icc_set_bw(q6v5->path, 0, 0);
> > >    		return ret;
> > > +	}
> > >    	reinit_completion(&q6v5->start_done);
> > >    	reinit_completion(&q6v5->stop_done);
> > > @@ -78,6 +87,9 @@ int qcom_q6v5_unprepare(struct qcom_q6v5 *q6v5)
> > >    	disable_irq(q6v5->handover_irq);
> > >    	q6v5_load_state_toggle(q6v5, false);
> > > +	/* Disable interconnect vote, in case handover never happened */
> > > +	icc_set_bw(q6v5->path, 0, 0);
> > > +
> > >    	return !q6v5->handover_issued;
> > >    }
> > >    EXPORT_SYMBOL_GPL(qcom_q6v5_unprepare);
> > > @@ -160,6 +172,8 @@ static irqreturn_t q6v5_handover_interrupt(int irq, void *data)
> > >    	if (q6v5->handover)
> > >    		q6v5->handover(q6v5);
> > > +	icc_set_bw(q6v5->path, 0, 0);
> > > +
> > >    	q6v5->handover_issued = true;
> > >    	return IRQ_HANDLED;
> > > @@ -332,6 +346,11 @@ int qcom_q6v5_init(struct qcom_q6v5 *q6v5, struct platform_device *pdev,
> > >    		return load_state ? -ENOMEM : -EINVAL;
> > >    	}
> > > +	q6v5->path = devm_of_icc_get(&pdev->dev, NULL);
> > > +	if (IS_ERR(q6v5->path))
> > > +		return dev_err_probe(&pdev->dev, PTR_ERR(q6v5->path),
> > > +				     "failed to acquire interconnect path\n");
> > > +
> > >    	return 0;
> > >    }
> > >    EXPORT_SYMBOL_GPL(qcom_q6v5_init);
> >
> > Probably we should also call icc_put(q6v5->path) in qcom_q6v5_deinit().
>
> The use of devm_of_icc_get() should take care of that for us. Or am I
> missing something?

Right, it's fine then. Sorry for the noise.

BR,
Georgi

> > Reviewed-by: Georgi Djakov <djakov@xxxxxxxxxx>
>
> Thanks,
> Bjorn