Re: [Patch v1 01/10] memory: tegra: add interconnect support for DRAM scaling in Tegra234

[Sumit Gupta]

On 21/12/22 22:24, Dmitry Osipenko wrote:
> External email: Use caution opening links or attachments
>
>
> 20.12.2022 19:02, Sumit Gupta пишет:
> >   static int tegra186_emc_probe(struct platform_device *pdev)
> >   {
> >        struct mrq_emc_dvfs_latency_response response;
> >        struct tegra_bpmp_message msg;
> >        struct tegra186_emc *emc;
> > +     struct tegra_mc *mc;
> >        unsigned int i;
> >        int err;
> >
> > @@ -158,6 +307,9 @@ static int tegra186_emc_probe(struct platform_device *pdev)
> >        if (!emc)
> >                return -ENOMEM;
> >
> > +     platform_set_drvdata(pdev, emc);
> > +     emc->dev = &pdev->dev;
> > +
> >        emc->bpmp = tegra_bpmp_get(&pdev->dev);
> >        if (IS_ERR(emc->bpmp))
> >                return dev_err_probe(&pdev->dev, PTR_ERR(emc->bpmp), "failed to get BPMP\n");
> > @@ -236,6 +388,19 @@ static int tegra186_emc_probe(struct platform_device *pdev)
> >        debugfs_create_file("max_rate", S_IRUGO | S_IWUSR, emc->debugfs.root,
> >                            emc, &tegra186_emc_debug_max_rate_fops);
> >
> > +     mc = dev_get_drvdata(emc->dev->parent);
> > +     if (mc && mc->soc->icc_ops) {
> > +             if (tegra_bpmp_mrq_is_supported(emc->bpmp, MRQ_BWMGR_INT)) {
> > +                     err = tegra_emc_interconnect_init(emc);
> > +                     if (!err)
> > +                             return err;
> > +                     dev_err(&pdev->dev, "tegra_emc_interconnect_init failed:%d\n", err);
> > +                     goto put_bpmp;
> > +             } else {
> > +                     dev_info(&pdev->dev, "MRQ_BWMGR_INT not present\n");
> > +             }
>
> If there is no MRQ_BWMGR_INT, then device drivers using ICC won't probe.
> This is either a error condition, or ICC should inited and then ICC
> changes should be skipped.

If the MRQ_BW_MGR is not supported by a BPMP-FW binary, then the MC & 
EMC drivers will still probe successfully and scaling will be disabled.