Re: [PATCH v1 4/4] PM / devfreq: tegra30: Check whether clk_round_rate() returns zero rate

From: Chanwoo Choi <cwchoi00@gmail.com>
To: Dmitry Osipenko <digetx@gmail.com>,
	Thierry Reding <thierry.reding@gmail.com>,
	Jonathan Hunter <jonathanh@nvidia.com>,
	Viresh Kumar <vireshk@kernel.org>, Nishanth Menon <nm@ti.com>,
	MyungJoo Ham <myungjoo.ham@samsung.com>,
	Stephen Boyd <sboyd@kernel.org>,
	Kyungmin Park <kyungmin.park@samsung.com>,
	Chanwoo Choi <cw00.choi@samsung.com>
Cc: linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-pm@vger.kernel.org
Subject: Re: [PATCH v1 4/4] PM / devfreq: tegra30: Check whether clk_round_rate() returns zero rate
Date: Wed, 15 Sep 2021 12:51:11 +0900	[thread overview]
Message-ID: <9fa66405-883a-3653-eb5d-3cd7eee07a0a@gmail.com> (raw)
In-Reply-To: <20210912184458.17995-5-digetx@gmail.com>

Hi,

On 21. 9. 13. 오전 3:44, Dmitry Osipenko wrote:
> EMC clock is always-on and can't be zero. Check whether clk_round_rate()
> returns zero rate and error out if it does. It can return zero if clock
> tree isn't initialized properly.
> 
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> ---
>   drivers/devfreq/tegra30-devfreq.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/devfreq/tegra30-devfreq.c b/drivers/devfreq/tegra30-devfreq.c
> index d83fdc2713ed..65ecf17a36f4 100644
> --- a/drivers/devfreq/tegra30-devfreq.c
> +++ b/drivers/devfreq/tegra30-devfreq.c
> @@ -891,9 +891,9 @@ static int tegra_devfreq_probe(struct platform_device *pdev)
>   		return err;
>   
>   	rate = clk_round_rate(tegra->emc_clock, ULONG_MAX);
> -	if (rate < 0) {
> +	if (rate <= 0) {
>   		dev_err(&pdev->dev, "Failed to round clock rate: %ld\n", rate);
> -		return rate;
> +		return rate ?: -EINVAL;
>   	}
>   
>   	tegra->max_freq = rate / KHZ;
> 

Acked-by: Chanwoo Choi <cw00.choi@samsung.com>

-- 
Best Regards,
Samsung Electronics
Chanwoo Choi