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* [PATCH v2 1/6] cpufreq: dt: disable unsupported OPPs
@ 2014-09-26 13:40 Lucas Stach
  2014-09-26 13:41 ` [PATCH v2 2/6] clk: imx5: add step clock, used when reprogramming PLL1 Lucas Stach
                   ` (5 more replies)
  0 siblings, 6 replies; 14+ messages in thread
From: Lucas Stach @ 2014-09-26 13:40 UTC (permalink / raw)
  To: Shawn Guo, Rafael J. Wysocki, Viresh Kumar
  Cc: Mark Brown, linux-pm, linux-arm-kernel, kernel

If the regulator connected to the CPU voltage plane doesn't
support an OPP specified voltage with the acceptable tolerance
it's better to just disable the OPP instead of constantly
failing the voltage scaling later on.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
---
v2:
- rebase on top of pm/linux-next
---
 drivers/cpufreq/cpufreq-dt.c | 66 +++++++++++++++++++++++++++-----------------
 1 file changed, 40 insertions(+), 26 deletions(-)

diff --git a/drivers/cpufreq/cpufreq-dt.c b/drivers/cpufreq/cpufreq-dt.c
index 6bbb8b913446..4485c8eccdc2 100644
--- a/drivers/cpufreq/cpufreq-dt.c
+++ b/drivers/cpufreq/cpufreq-dt.c
@@ -185,6 +185,7 @@ static int cpufreq_init(struct cpufreq_policy *policy)
 	struct device *cpu_dev;
 	struct regulator *cpu_reg;
 	struct clk *cpu_clk;
+	unsigned long min_uV = ~0, max_uV = 0;
 	unsigned int transition_latency;
 	int ret;
 
@@ -204,16 +205,10 @@ static int cpufreq_init(struct cpufreq_policy *policy)
 	/* OPPs might be populated at runtime, don't check for error here */
 	of_init_opp_table(cpu_dev);
 
-	ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table);
-	if (ret) {
-		dev_err(cpu_dev, "failed to init cpufreq table: %d\n", ret);
-		goto out_put_node;
-	}
-
 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 	if (!priv) {
 		ret = -ENOMEM;
-		goto out_free_table;
+		goto out_put_node;
 	}
 
 	of_property_read_u32(np, "voltage-tolerance", &priv->voltage_tolerance);
@@ -222,30 +217,49 @@ static int cpufreq_init(struct cpufreq_policy *policy)
 		transition_latency = CPUFREQ_ETERNAL;
 
 	if (!IS_ERR(cpu_reg)) {
-		struct dev_pm_opp *opp;
-		unsigned long min_uV, max_uV;
-		int i;
-
 		/*
-		 * OPP is maintained in order of increasing frequency, and
-		 * freq_table initialised from OPP is therefore sorted in the
-		 * same order.
+		 * Disable any OPPs where the connected regulator isn't able to
+		 * provide the specified voltage and record minimum and maximum
+		 * voltage levels.
 		 */
-		for (i = 0; freq_table[i].frequency != CPUFREQ_TABLE_END; i++)
-			;
-		rcu_read_lock();
-		opp = dev_pm_opp_find_freq_exact(cpu_dev,
-				freq_table[0].frequency * 1000, true);
-		min_uV = dev_pm_opp_get_voltage(opp);
-		opp = dev_pm_opp_find_freq_exact(cpu_dev,
-				freq_table[i-1].frequency * 1000, true);
-		max_uV = dev_pm_opp_get_voltage(opp);
-		rcu_read_unlock();
+		while (1) {
+			struct dev_pm_opp *opp;
+			unsigned long opp_freq = 0, opp_uV, tol_uV;
+
+			rcu_read_lock();
+			opp = dev_pm_opp_find_freq_ceil(cpu_dev, &opp_freq);
+			if (IS_ERR(opp)) {
+				rcu_read_unlock();
+				break;
+			}
+			opp_uV = dev_pm_opp_get_voltage(opp);
+			rcu_read_unlock();
+
+			tol_uV = opp_uV * priv->voltage_tolerance / 100;
+			if (regulator_is_supported_voltage(cpu_reg, opp_uV,
+							   opp_uV + tol_uV)) {
+				if (opp_uV < min_uV)
+					min_uV = opp_uV;
+				if (opp_uV > max_uV)
+					max_uV = opp_uV;
+			} else {
+				dev_pm_opp_disable(cpu_dev, opp_freq);
+			}
+
+			opp_freq++;
+		}
+
 		ret = regulator_set_voltage_time(cpu_reg, min_uV, max_uV);
 		if (ret > 0)
 			transition_latency += ret * 1000;
 	}
 
+	ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table);
+	if (ret) {
+		pr_err("failed to init cpufreq table: %d\n", ret);
+		goto out_free_priv;
+	}
+
 	/*
 	 * For now, just loading the cooling device;
 	 * thermal DT code takes care of matching them.
@@ -275,9 +289,9 @@ static int cpufreq_init(struct cpufreq_policy *policy)
 
 out_cooling_unregister:
 	cpufreq_cooling_unregister(priv->cdev);
-	kfree(priv);
-out_free_table:
 	dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table);
+out_free_priv:
+	kfree(priv);
 out_put_node:
 	of_node_put(np);
 out_put_reg_clk:
-- 
2.1.0


^ permalink raw reply related	[flat|nested] 14+ messages in thread

end of thread, other threads:[~2014-10-04 19:36 UTC | newest]

Thread overview: 14+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2014-09-26 13:40 [PATCH v2 1/6] cpufreq: dt: disable unsupported OPPs Lucas Stach
2014-09-26 13:41 ` [PATCH v2 2/6] clk: imx5: add step clock, used when reprogramming PLL1 Lucas Stach
2014-09-28  4:13   ` Shawn Guo
2014-09-26 13:41 ` [PATCH v2 3/6] clk: imx: add CPU clock type Lucas Stach
2014-09-26 13:41 ` [PATCH v2 4/6] arm: imx53: clk: add ARM clock Lucas Stach
2014-09-26 13:41 ` [PATCH v2 5/6] ARM: dts: imx53: add cpufreq-dt support Lucas Stach
2014-10-04 19:36   ` Stefan Wahren
2014-09-26 13:41 ` [PATCH v2 6/6] ARM: imx53: add cpufreq support Lucas Stach
2014-09-28  4:15   ` Shawn Guo
2014-09-29  8:33     ` Lucas Stach
2014-09-29 12:00       ` Shawn Guo
2014-09-26 21:55 ` [PATCH v2 1/6] cpufreq: dt: disable unsupported OPPs Rafael J. Wysocki
2014-09-29  8:24   ` Lucas Stach
2014-09-29 23:42     ` Rafael J. Wysocki

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