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From:   "Rafael J. Wysocki" <rafael@kernel.org>
Date:   Mon, 11 Jan 2021 13:44:09 +0100
Message-ID: <CAJZ5v0i5F3kFOxzAax1RS9etrLtzLBuPRoqvbQM=NwuonFZDVw@mail.gmail.com>
Subject: Re: [PATCH 1/2][v2] cpufreq: intel_pstate: Add parameter to get
 guarantee frequency
To:     Chen Yu <yu.c.chen@intel.com>
Cc:     Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>,
        Len Brown <lenb@kernel.org>,
        "Rafael J. Wysocki" <rjw@rjwysocki.net>,
        Viresh Kumar <viresh.kumar@linaro.org>,
        Linux PM <linux-pm@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Zhang Rui <rui.zhang@intel.com>,
        Wendy Wang <wendy.wang@intel.com>
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On Mon, Jan 11, 2021 at 8:40 AM Chen Yu <yu.c.chen@intel.com> wrote:
>
> Add input parameter to receive guarantee pstate from intel_pstate_get_hwp_max()
> for later use.

I'm not a fan of this change, because the new argument will only be
needed in one place where intel_pstate_get_hwp_max() and it requires
adding redundant local vars and pointless updates elsewhere.

Besides, in intel_pstate_get_cpu_pstates() you can do something like
this after calling intel_pstate_get_hwp_max():

cpu->pstate.max_pstate = HWP_GUARANTEED_PERF(READ_ONCE(cpu->hwp_cap_cached));
cpu->pstate.max_freq = cpu->pstate.max_pstate * cpu->pstate.scaling;