From:   Douglas Anderson <dianders@chromium.org>
To:     Viresh Kumar <viresh.kumar@linaro.org>,
        Manivannan Sadhasivam <mani@kernel.org>
Cc:     swboyd@chromium.org, mka@chromium.org,
        Douglas Anderson <dianders@chromium.org>,
        Andy Gross <agross@kernel.org>,
        Bjorn Andersson <andersson@kernel.org>,
        Konrad Dybcio <konrad.dybcio@linaro.org>,
        "Rafael J. Wysocki" <rafael@kernel.org>,
        Sasha Levin <sashal@kernel.org>, linux-arm-msm@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org
Subject: [PATCH] cpufreq: qcom-hw: Fix cpufreq_driver->get() for non-LMH systems
Date:   Thu,  2 Feb 2023 14:00:23 -0800
Message-Id: <20230202140005.1.I4b30aaa027c73372ec4068cc0f0dc665af8b938d@changeid>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

On a sc7180-based Chromebook, when I go to
/sys/devices/system/cpu/cpu0/cpufreq I can see:

  cpuinfo_cur_freq:2995200
  cpuinfo_max_freq:1804800
  scaling_available_frequencies:300000 576000 ... 1708800 1804800
  scaling_cur_freq:1804800
  scaling_max_freq:1804800

As you can see the `cpuinfo_cur_freq` is bogus. It turns out that this
bogus info started showing up as of commit 205f5e984d30 ("cpufreq:
qcom-hw: Fix the frequency returned by cpufreq_driver->get()"). That
commit seems to assume that everyone is on the LMH bandwagon, but
sc7180 isn't.

Let's go back to the old code in the case where LMH isn't used.

Fixes: 205f5e984d30 ("cpufreq: qcom-hw: Fix the frequency returned by cpufreq_driver->get()")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
---

 drivers/cpufreq/qcom-cpufreq-hw.c | 24 +++++++++++++-----------
 1 file changed, 13 insertions(+), 11 deletions(-)

diff --git a/drivers/cpufreq/qcom-cpufreq-hw.c b/drivers/cpufreq/qcom-cpufreq-hw.c
index 9505a812d6a1..957cf6bb8c05 100644
--- a/drivers/cpufreq/qcom-cpufreq-hw.c
+++ b/drivers/cpufreq/qcom-cpufreq-hw.c
@@ -143,40 +143,42 @@ static unsigned long qcom_lmh_get_throttle_freq(struct qcom_cpufreq_data *data)
 	return lval * xo_rate;
 }
 
-/* Get the current frequency of the CPU (after throttling) */
-static unsigned int qcom_cpufreq_hw_get(unsigned int cpu)
+/* Get the frequency requested by the cpufreq core for the CPU */
+static unsigned int qcom_cpufreq_get_freq(unsigned int cpu)
 {
 	struct qcom_cpufreq_data *data;
+	const struct qcom_cpufreq_soc_data *soc_data;
 	struct cpufreq_policy *policy;
+	unsigned int index;
 
 	policy = cpufreq_cpu_get_raw(cpu);
 	if (!policy)
 		return 0;
 
 	data = policy->driver_data;
+	soc_data = qcom_cpufreq.soc_data;
 
-	return qcom_lmh_get_throttle_freq(data) / HZ_PER_KHZ;
+	index = readl_relaxed(data->base + soc_data->reg_perf_state);
+	index = min(index, LUT_MAX_ENTRIES - 1);
+
+	return policy->freq_table[index].frequency;
 }
 
-/* Get the frequency requested by the cpufreq core for the CPU */
-static unsigned int qcom_cpufreq_get_freq(unsigned int cpu)
+static unsigned int qcom_cpufreq_hw_get(unsigned int cpu)
 {
 	struct qcom_cpufreq_data *data;
-	const struct qcom_cpufreq_soc_data *soc_data;
 	struct cpufreq_policy *policy;
-	unsigned int index;
 
 	policy = cpufreq_cpu_get_raw(cpu);
 	if (!policy)
 		return 0;
 
 	data = policy->driver_data;
-	soc_data = qcom_cpufreq.soc_data;
 
-	index = readl_relaxed(data->base + soc_data->reg_perf_state);
-	index = min(index, LUT_MAX_ENTRIES - 1);
+	if (data->throttle_irq >= 0)
+		return qcom_lmh_get_throttle_freq(data) / HZ_PER_KHZ;
 
-	return policy->freq_table[index].frequency;
+	return qcom_cpufreq_get_freq(cpu);
 }
 
 static unsigned int qcom_cpufreq_hw_fast_switch(struct cpufreq_policy *policy,
-- 
2.39.1.519.gcb327c4b5f-goog