Re: [PATCH v5 3/4] remoteproc: imx_dsp_rproc: Add remoteproc driver for DSP on i.MX

Mathieu Poirier
2021-10-08T15:43:07Z

On Fri, Oct 08, 2021 at 09:53:18AM +0800, Shengjiu Wang wrote:
> Hi Mathieu
>
> On Thu, Oct 7, 2021 at 12:25 AM Mathieu Poirier
> <mathieu.poirier@linaro.org> wrote:
> >
> > Hi Shengjiu,
> >
> > This pachset doesn't apply to rproc-next, which is now located here[1]. The
> > change is in linux-next but not in mainline yet.
> >
> > https://git.kernel.org/pub/scm/linux/kernel/git/remoteproc/linux.git/log/?h=rproc-next
>
> Ok, I will double check it and fix it.
>
> >
> > On Sun, Sep 26, 2021 at 11:07:09AM +0800, Shengjiu Wang wrote:
> > > Provide a basic driver to control DSP processor found on NXP i.MX8QM,
> > > i.MX8QXP, i.MX8MP and i.MX8ULP.
> > >
> > > Currently it is able to resolve addresses between DSP and main CPU,
> > > start and stop the processor, suspend and resume.
> > >
> > > The communication between DSP and main CPU is based on mailbox, there
> > > are three mailbox channels (tx, rx, rxdb).
> > >
> > > This driver was tested on NXP i.MX8QM, i.MX8QXP, i.MX8MP and i.MX8ULP.
> > >
> > > Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
> > > ---
> > > drivers/remoteproc/Kconfig | 11 +
> > > drivers/remoteproc/Makefile | 1 +
> > > drivers/remoteproc/imx_dsp_rproc.c | 1206 ++++++++++++++++++++++++++++
> > > 3 files changed, 1218 insertions(+)
> > > create mode 100644 drivers/remoteproc/imx_dsp_rproc.c
> > >
> >
> > [...]
> >
> > > +
> > > +/**
> > > + * imx_dsp_attach_pm_domains() - attach the power domains
> > > + * @priv: private data pointer
> > > + *
> > > + * On i.MX8QM and i.MX8QXP there is multiple power domains
> > > + * required, so need to link them.
> > > + */
> > > +static int imx_dsp_attach_pm_domains(struct imx_dsp_rproc *priv)
> > > +{
> > > + struct device *dev = priv->rproc->dev.parent;
> > > + int ret, i;
> > > +
> > > + priv->num_domains = of_count_phandle_with_args(dev->of_node,
> > > + "power-domains",
> > > + "#power-domain-cells");
> > > +
> > > + /* If only one domain, then no need to link the device */
> > > + if (priv->num_domains <= 1)
> > > + return 0;
> > > +
> > > + priv->pd_dev = devm_kmalloc_array(dev, priv->num_domains,
> > > + sizeof(*priv->pd_dev),
> > > + GFP_KERNEL);
> > > + if (!priv->pd_dev)
> > > + return -ENOMEM;
> > > +
> > > + priv->pd_dev_link = devm_kmalloc_array(dev, priv->num_domains,
> > > + sizeof(*priv->pd_dev_link),
> > > + GFP_KERNEL);
> > > + if (!priv->pd_dev_link)
> > > + return -ENOMEM;
> > > +
> > > + for (i = 0; i < priv->num_domains; i++) {
> > > + priv->pd_dev[i] = dev_pm_domain_attach_by_id(dev, i);
> > > + if (IS_ERR(priv->pd_dev[i])) {
> > > + ret = PTR_ERR(priv->pd_dev[i]);
> > > + goto detach_pm;
> > > + }
> >
> > I have pointed a problem with the error handling in the above during the
> > previous review and it was not addressed.
>
> I have considered your comments. Actually when
> dev_pm_domain_attach_by_id() return NULL, the device_link_add()
> will break, I have added comments below, so above error handling
> for dev_pm_domain_attach_by_id() is enough.

I would have used IS_ERR_OR_NULL() so that potential code inserted between the
two function doesn't automatically assume priv->pd_dev[i] is valid. But what
you have here will work.

Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>

> Best regards
> Wang Shengjiu
> >
> > > +
> > > + /*
> > > + * device_link_add will check priv->pd_dev[i], if it is
> > > + * NULL, then will break.
> > > + */
> > > + priv->pd_dev_link[i] = device_link_add(dev,
> > > + priv->pd_dev[i],
> > > + DL_FLAG_STATELESS |
> > > + DL_FLAG_PM_RUNTIME);
> > > + if (!priv->pd_dev_link[i]) {
> > > + dev_pm_domain_detach(priv->pd_dev[i], false);
> > > + ret = -EINVAL;
> > > + goto detach_pm;
> > > + }
> > > + }
> > > +
> > > + return 0;
> > > +
> > > +detach_pm:
> > > + while (--i >= 0) {
> > > + device_link_del(priv->pd_dev_link[i]);
> > > + dev_pm_domain_detach(priv->pd_dev[i], false);
> > > + }
> > > +
> > > + return ret;
> > > +}
> > > +