Commit 067b7ce0 authored by Jisheng Zhang's avatar Jisheng Zhang Committed by Rafael J. Wysocki
Browse files

PM / OPP: optimize dev_pm_opp_set_rate() performance a bit 



In dev_pm_opp_set_rate(), _find_opp_table() is called 4 times: once by
_get_opp_clk(), once by dev_pm_opp_set_rate() itself, and twice by
dev_pm_opp_find_freq_ceil(). If there are several opp_tables in the
system, three times of opp table finding is a big waste. This patch
reduced the call of _find_opp_table() to twice.

Signed-off-by: default avatarJisheng Zhang <jszhang@marvell.com>
Acked-by: default avatarViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 523d939e

drivers/base/power/opp/core.c

+19 −12
Original line number Diff line number Diff line
@@ -402,6 +402,22 @@ struct dev_pm_opp *dev_pm_opp_find_freq_exact(struct device *dev, 
}

EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_exact);



static noinline struct dev_pm_opp *_find_freq_ceil(struct opp_table *opp_table,

						   unsigned long *freq)

{

	struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE);



	list_for_each_entry_rcu(temp_opp, &opp_table->opp_list, node) {

		if (temp_opp->available && temp_opp->rate >= *freq) {

			opp = temp_opp;

			*freq = opp->rate;

			break;

		}

	}



	return opp;

}



/**

 * dev_pm_opp_find_freq_ceil() - Search for an rounded ceil freq

 * @dev:	device for which we do this operation
@@ -427,7 +443,6 @@ struct dev_pm_opp *dev_pm_opp_find_freq_ceil(struct device *dev, 
					     unsigned long *freq)

{

	struct opp_table *opp_table;

	struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE);



	opp_rcu_lockdep_assert();
@@ -440,15 +455,7 @@ struct dev_pm_opp *dev_pm_opp_find_freq_ceil(struct device *dev, 
	if (IS_ERR(opp_table))

		return ERR_CAST(opp_table);



	list_for_each_entry_rcu(temp_opp, &opp_table->opp_list, node) {

		if (temp_opp->available && temp_opp->rate >= *freq) {

			opp = temp_opp;

			*freq = opp->rate;

			break;

		}

	}



	return opp;

	return _find_freq_ceil(opp_table, freq);

}

EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_ceil);
@@ -612,7 +619,7 @@ int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq) 
		return PTR_ERR(opp_table);

	}



	old_opp = dev_pm_opp_find_freq_ceil(dev, &old_freq);

	old_opp = _find_freq_ceil(opp_table, &old_freq);

	if (!IS_ERR(old_opp)) {

		ou_volt = old_opp->u_volt;

		ou_volt_min = old_opp->u_volt_min;
@@ -622,7 +629,7 @@ int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq) 
			__func__, old_freq, PTR_ERR(old_opp));

	}



	opp = dev_pm_opp_find_freq_ceil(dev, &freq);

	opp = _find_freq_ceil(opp_table, &freq);

	if (IS_ERR(opp)) {

		ret = PTR_ERR(opp);

		dev_err(dev, "%s: failed to find OPP for freq %lu (%d)\n",

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