Re: [PATCH] cpufreq: cpufreq-cpu0: use the exact frequency forclk_set_rate()

From: Guennadi Liakhovetski
Date: Wed Mar 27 2013 - 18:46:52 EST


Hi Shawn

On Mon, 25 Feb 2013, Guennadi Liakhovetski wrote:

> clk_set_rate() isn't supposed to accept approximate frequencies, instead
> a supported frequency should be obtained from clk_round_rate() and then
> used to set the clock.
>
> Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@xxxxxx>

Can I have your ack for this one, please?

Thanks
Guennadi

> ---
>
> Applies on top of my previous patch to fix unsigned freq_Hz "cpufreq: fix
> sign check of an unsigned variable in cpufreq-cpu0"
>
> drivers/cpufreq/cpufreq-cpu0.c | 5 +++--
> 1 files changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/cpufreq/cpufreq-cpu0.c b/drivers/cpufreq/cpufreq-cpu0.c
> index e7bad3c..6ce9b51 100644
> --- a/drivers/cpufreq/cpufreq-cpu0.c
> +++ b/drivers/cpufreq/cpufreq-cpu0.c
> @@ -45,7 +45,7 @@ static int cpu0_set_target(struct cpufreq_policy *policy,
> struct cpufreq_freqs freqs;
> struct opp *opp;
> unsigned long volt = 0, volt_old = 0, tol = 0;
> - long freq_Hz;
> + long freq_Hz, freq_exact;
> unsigned int index, cpu;
> int ret;
>
> @@ -60,6 +60,7 @@ static int cpu0_set_target(struct cpufreq_policy *policy,
> freq_Hz = clk_round_rate(cpu_clk, freq_table[index].frequency * 1000);
> if (freq_Hz < 0)
> freq_Hz = freq_table[index].frequency * 1000;
> + freq_exact = freq_Hz;
> freqs.new = freq_Hz / 1000;
> freqs.old = clk_get_rate(cpu_clk) / 1000;
>
> @@ -96,7 +97,7 @@ static int cpu0_set_target(struct cpufreq_policy *policy,
> }
> }
>
> - ret = clk_set_rate(cpu_clk, freqs.new * 1000);
> + ret = clk_set_rate(cpu_clk, freq_exact);
> if (ret) {
> pr_err("failed to set clock rate: %d\n", ret);
> if (cpu_reg)
> --
> 1.7.2.5
>
>

---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/
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