linux-kernel - Re: [PATCH 2/2] cpufreq: brcmstb-avs-cpufreq: properly retrieve P-state upon suspend

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Message-ID: <20170106041112.GC21926@vireshk-i7>
Date:   Fri, 6 Jan 2017 09:41:12 +0530
From:   Viresh Kumar <viresh.kumar@...aro.org>
To:     Markus Mayer <code@...yer.net>
Cc:     "Rafael J . Wysocki" <rjw@...ysocki.net>,
        Power Management List <linux-pm@...r.kernel.org>,
        Broadcom Kernel List <bcm-kernel-feedback-list@...adcom.com>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        Markus Mayer <mmayer@...adcom.com>
Subject: Re: [PATCH 2/2] cpufreq: brcmstb-avs-cpufreq: properly retrieve
 P-state upon suspend

On 19-12-16, 12:10, Markus Mayer wrote:
> From: Markus Mayer <mmayer@...adcom.com>
> 
> The AVS GET_PMAP command does return a P-state along with the P-map
> information. However, that P-state is the initial P-state when the
> P-map was first downloaded to AVS. It is *not* the current P-state.
> 
> Therefore, we explicitly retrieve the P-state using the GET_PSTATE
> command.
> 
> Signed-off-by: Markus Mayer <mmayer@...adcom.com>
> ---
>  drivers/cpufreq/brcmstb-avs-cpufreq.c | 13 ++++++++++++-
>  1 file changed, 12 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/cpufreq/brcmstb-avs-cpufreq.c b/drivers/cpufreq/brcmstb-avs-cpufreq.c
> index 2c6e325..c943606 100644
> --- a/drivers/cpufreq/brcmstb-avs-cpufreq.c
> +++ b/drivers/cpufreq/brcmstb-avs-cpufreq.c
> @@ -784,8 +784,19 @@ static int brcm_avs_target_index(struct cpufreq_policy *policy,
>  static int brcm_avs_suspend(struct cpufreq_policy *policy)
>  {
>  	struct private_data *priv = policy->driver_data;
> +	int ret;
> +
> +	ret = brcm_avs_get_pmap(priv, &priv->pmap);
> +	if (ret)
> +		return ret;
>  
> -	return brcm_avs_get_pmap(priv, &priv->pmap);
> +	/*
> +	 * We can't use the P-state returned by brcm_avs_get_pmap(), since
> +	 * that's the initial P-state from when the P-map was downloaded to the
> +	 * AVS co-processor, not necessarily the P-state we are running at now.
> +	 * So, we get the current P-state explicitly.
> +	 */
> +	return brcm_avs_get_pstate(priv, &priv->pmap.state);
>  }
>  
>  static int brcm_avs_resume(struct cpufreq_policy *policy)

Acked-by: Viresh Kumar <viresh.kumar@...aro.org>

-- 
viresh