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Re: [PATCH] cpufreq: arm_big_little: fix frequency check when bL switcher is active

From Sudeep Holla <sudeep.holla@arm.com>
Newsgroups linux.kernel
Subject Re: [PATCH] cpufreq: arm_big_little: fix frequency check when bL switcher is active
Date 2015-10-12 15:30 +0200
Message-ID <qiLkR-cI-1@gated-at.bofh.it> (permalink)
References <qfctk-1MB-17@gated-at.bofh.it> <qh0R5-3eS-21@gated-at.bofh.it> <qhfGq-7Lv-23@gated-at.bofh.it>
Organization linux.* mail to news gateway

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On 08/10/15 10:23, Jon Medhurst (Tixy) wrote:
[...]

> diff --git a/drivers/cpufreq/arm_big_little.c b/drivers/cpufreq/arm_big_little.c
> index f1e42f8..59115a4 100644
> --- a/drivers/cpufreq/arm_big_little.c
> +++ b/drivers/cpufreq/arm_big_little.c
> @@ -149,6 +149,18 @@ bL_cpufreq_set_rate(u32 cpu, u32 old_cluster, u32 new_cluster, u32 rate)
>   			__func__, cpu, old_cluster, new_cluster, new_rate);
>
>   	ret = clk_set_rate(clk[new_cluster], new_rate * 1000);
> +	if (!ret) {
> +		/*
> +		 * FIXME: clk_set_rate has to handle the case where clk_change_rate
> +		 * can fail due to hardware or firmware issues. Until the clk core
> +		 * layer is fixed, we can check here. In most of the cases we will
> +		 * be reading only the cached value anyway. This needs to  be removed
> +		 * once clk core is fixed.
> +		 */
> +		if (clk_get_rate(clk[new_cluster]) != new_rate * 1000)
> +			ret = -EIO;
> +	}
> +
>   	if (WARN_ON(ret)) {
>   		pr_err("clk_set_rate failed: %d, new cluster: %d\n", ret,
>   				new_cluster);
> @@ -189,15 +201,6 @@ bL_cpufreq_set_rate(u32 cpu, u32 old_cluster, u32 new_cluster, u32 rate)
>   		mutex_unlock(&cluster_lock[old_cluster]);
>   	}
>
> -	/*
> -	 * FIXME: clk_set_rate has to handle the case where clk_change_rate
> -	 * can fail due to hardware or firmware issues. Until the clk core
> -	 * layer is fixed, we can check here. In most of the cases we will
> -	 * be reading only the cached value anyway. This needs to  be removed
> -	 * once clk core is fixed.
> -	 */
> -	if (bL_cpufreq_get_rate(cpu) != new_rate)
> -		return -EIO;
>   	return 0;
>   }
>
>
>
>

The above change looks good to me but with minor nit. You can get rid of
if(!ret) check if you move the hunk after if (WARN_ON(ret))

-- 
Regards, Sudeep
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Thread

Re: [PATCH] cpufreq: arm_big_little: fix frequency check when bL  switcher is active Viresh Kumar <viresh.kumar@linaro.org> - 2015-10-07 19:40 +0200
  Re: [PATCH] cpufreq: arm_big_little: fix frequency check when bL  switcher is active "Jon Medhurst (Tixy)" <tixy@linaro.org> - 2015-10-08 11:30 +0200
    Re: [PATCH] cpufreq: arm_big_little: fix frequency check when bL  switcher is active Viresh Kumar <viresh.kumar@linaro.org> - 2015-10-08 13:30 +0200
      Re: [PATCH] cpufreq: arm_big_little: fix frequency check when bL  switcher is active "Jon Medhurst (Tixy)" <tixy@linaro.org> - 2015-10-08 15:00 +0200
        Re: [PATCH] cpufreq: arm_big_little: fix frequency check when bL  switcher is active Viresh Kumar <viresh.kumar@linaro.org> - 2015-10-08 16:00 +0200
        Re: [PATCH] cpufreq: arm_big_little: fix frequency check when bL  switcher is active Sudeep Holla <sudeep.holla@foss.arm.com> - 2015-10-08 16:20 +0200
    Re: [PATCH] cpufreq: arm_big_little: fix frequency check when bL  switcher is active Sudeep Holla <sudeep.holla@arm.com> - 2015-10-12 15:30 +0200
      Re: [PATCH] cpufreq: arm_big_little: fix frequency check when bL  switcher is active "Jon Medhurst (Tixy)" <tixy@linaro.org> - 2015-10-13 09:20 +0200
        Re: [PATCH] cpufreq: arm_big_little: fix frequency check when bL  switcher is active Sudeep Holla <sudeep.holla@arm.com> - 2015-10-13 12:40 +0200
          Re: [PATCH] cpufreq: arm_big_little: fix frequency check when bL  switcher is active "Jon Medhurst (Tixy)" <tixy@linaro.org> - 2015-10-14 09:20 +0200
            Re: [PATCH] cpufreq: arm_big_little: fix frequency check when bL  switcher is active Sudeep Holla <sudeep.holla@arm.com> - 2015-10-14 10:50 +0200

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