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Date:   Fri, 1 Sep 2023 18:59:24 +0100
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Subject: Re: [Patch v2 2/2] cpufreq: tegra194: use refclk delta based loop
 instead of udelay
Content-Language: en-US
To:     Sumit Gupta <sumitg@nvidia.com>, rafael@kernel.org,
        viresh.kumar@linaro.org, linux-pm@vger.kernel.org,
        linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org
Cc:     treding@nvidia.com, bbasu@nvidia.com, amiettinen@nvidia.com
References: <20230901164113.29139-1-sumitg@nvidia.com>
 <20230901164113.29139-3-sumitg@nvidia.com>
From:   Jon Hunter <jonathanh@nvidia.com>
In-Reply-To: <20230901164113.29139-3-sumitg@nvidia.com>
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On 01/09/2023 17:41, Sumit Gupta wrote:
> Use reference clock count based loop instead of "udelay()" for
> sampling of counters to improve the accuracy of re-generated CPU
> frequency. "udelay()" internally calls "WFE" which stops the
> counters and results in bigger delta between the last set freq
> and the re-generated value from counters. The counter sampling
> window used in loop is the minimum number of reference clock
> cycles which is known to give a stable value of CPU frequency.
> The change also helps to reduce the sampling window from "500us"
> to "<50us".
> 
> Suggested-by: Antti Miettinen <amiettinen@nvidia.com>
> Signed-off-by: Sumit Gupta <sumitg@nvidia.com>
> ---

Same here.

Jon

-- 
nvpublic