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Message-ID: <8641fad2-7170-4c0c-fbd6-6e2e784b3106@gmail.com>
Date:   Wed, 21 Dec 2022 19:54:58 +0300
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Subject: Re: [Patch v1 01/10] memory: tegra: add interconnect support for DRAM
 scaling in Tegra234
Content-Language: en-US
To:     Sumit Gupta <sumitg@nvidia.com>, treding@nvidia.com,
        krzysztof.kozlowski@linaro.org, dmitry.osipenko@collabora.com,
        viresh.kumar@linaro.org, rafael@kernel.org, jonathanh@nvidia.com,
        robh+dt@kernel.org, linux-kernel@vger.kernel.org,
        linux-tegra@vger.kernel.org, linux-pm@vger.kernel.org,
        devicetree@vger.kernel.org
Cc:     sanjayc@nvidia.com, ksitaraman@nvidia.com, ishah@nvidia.com,
        bbasu@nvidia.com
References: <20221220160240.27494-1-sumitg@nvidia.com>
 <20221220160240.27494-2-sumitg@nvidia.com>
From:   Dmitry Osipenko <digetx@gmail.com>
In-Reply-To: <20221220160240.27494-2-sumitg@nvidia.com>
Content-Type: text/plain; charset=UTF-8
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Precedence: bulk

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.