Re: [PATCH 4/5] cpufreq: tegra186/tegra194: Handle errors in BPMP response

From: Viresh Kumar <viresh.kumar@linaro.org>
To: Mikko Perttunen <mperttunen@nvidia.com>
Cc: rafael@kernel.org, thierry.reding@gmail.com,
	jonathanh@nvidia.com, krzysztof.kozlowski@canonical.com,
	lorenzo.pieralisi@arm.com, robh@kernel.org, kw@linux.com,
	p.zabel@pengutronix.de, rui.zhang@intel.com,
	daniel.lezcano@linaro.org, amitk@kernel.org,
	linux-pm@vger.kernel.org, linux-tegra@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org
Subject: Re: [PATCH 4/5] cpufreq: tegra186/tegra194: Handle errors in BPMP response
Date: Mon, 4 Oct 2021 12:31:45 +0530	[thread overview]
Message-ID: <20211004070145.pp3rafkinffk2pyh@vireshk-i7> (raw)
In-Reply-To: <20210915085517.1669675-4-mperttunen@nvidia.com>

On 15-09-21, 11:55, Mikko Perttunen wrote:
> The return value from tegra_bpmp_transfer indicates the success or
> failure of the IPC transaction with BPMP. If the transaction
> succeeded, we also need to check the actual command's result code.
> Add code to do this.
> 
> While at it, explicitly handle missing CPU clusters, which can
> occur on floorswept chips. This worked before as well, but
> possibly only by accident.
> 
> Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
> ---
>  drivers/cpufreq/tegra186-cpufreq.c | 4 ++++
>  drivers/cpufreq/tegra194-cpufreq.c | 8 +++++++-
>  2 files changed, 11 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/cpufreq/tegra186-cpufreq.c b/drivers/cpufreq/tegra186-cpufreq.c
> index 5d1943e787b0..6c88827f4e62 100644
> --- a/drivers/cpufreq/tegra186-cpufreq.c
> +++ b/drivers/cpufreq/tegra186-cpufreq.c
> @@ -159,6 +159,10 @@ static struct cpufreq_frequency_table *init_vhint_table(
>  		table = ERR_PTR(err);
>  		goto free;
>  	}
> +	if (msg.rx.ret) {
> +		table = ERR_PTR(-EINVAL);
> +		goto free;
> +	}
>  
>  	for (i = data->vfloor; i <= data->vceil; i++) {
>  		u16 ndiv = data->ndiv[i];
> diff --git a/drivers/cpufreq/tegra194-cpufreq.c b/drivers/cpufreq/tegra194-cpufreq.c
> index a9620e4489ae..ac381db25dbe 100644
> --- a/drivers/cpufreq/tegra194-cpufreq.c
> +++ b/drivers/cpufreq/tegra194-cpufreq.c
> @@ -242,7 +242,7 @@ static int tegra194_cpufreq_init(struct cpufreq_policy *policy)
>  
>  	smp_call_function_single(policy->cpu, get_cpu_cluster, &cl, true);
>  
> -	if (cl >= data->num_clusters)
> +	if (cl >= data->num_clusters || !data->tables[cl])
>  		return -EINVAL;
>  
>  	/* set same policy for all cpus in a cluster */
> @@ -310,6 +310,12 @@ init_freq_table(struct platform_device *pdev, struct tegra_bpmp *bpmp,
>  	err = tegra_bpmp_transfer(bpmp, &msg);
>  	if (err)
>  		return ERR_PTR(err);
> +	if (msg.rx.ret == -BPMP_EINVAL) {
> +		/* Cluster not available */
> +		return NULL;
> +	}
> +	if (msg.rx.ret)
> +		return ERR_PTR(-EINVAL);
>  
>  	/*
>  	 * Make sure frequency table step is a multiple of mdiv to match

Applied. Thanks.

-- 
viresh