In dev_pm_opp_set_rate(), _find_opp_table() is called three times: once by _get_opp_clk(), 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 only once.
Signed-off-by: Jisheng Zhang <[email protected]> --- drivers/base/power/opp/core.c | 85 ++++++++++++++++++------------------------- 1 file changed, 36 insertions(+), 49 deletions(-) diff --git a/drivers/base/power/opp/core.c b/drivers/base/power/opp/core.c index 7c04c87..96043ee 100644 --- a/drivers/base/power/opp/core.c +++ b/drivers/base/power/opp/core.c @@ -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 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); @@ -506,34 +513,6 @@ struct dev_pm_opp *dev_pm_opp_find_freq_floor(struct device *dev, } EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_floor); -/* - * The caller needs to ensure that opp_table (and hence the clk) isn't freed, - * while clk returned here is used. - */ -static struct clk *_get_opp_clk(struct device *dev) -{ - struct opp_table *opp_table; - struct clk *clk; - - rcu_read_lock(); - - opp_table = _find_opp_table(dev); - if (IS_ERR(opp_table)) { - dev_err(dev, "%s: device opp doesn't exist\n", __func__); - clk = ERR_CAST(opp_table); - goto unlock; - } - - clk = opp_table->clk; - if (IS_ERR(clk)) - dev_err(dev, "%s: No clock available for the device\n", - __func__); - -unlock: - rcu_read_unlock(); - return clk; -} - static int _set_opp_voltage(struct device *dev, struct regulator *reg, unsigned long u_volt, unsigned long u_volt_min, unsigned long u_volt_max) @@ -586,9 +565,24 @@ int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq) return -EINVAL; } - clk = _get_opp_clk(dev); - if (IS_ERR(clk)) + rcu_read_lock(); + + opp_table = _find_opp_table(dev); + if (IS_ERR(opp_table)) { + dev_err(dev, "%s: device opp doesn't exist\n", __func__); + rcu_read_unlock(); + return PTR_ERR(opp_table); + } + + clk = opp_table->clk; + if (IS_ERR(clk)) { + dev_err(dev, "%s: No clock available for the device\n", + __func__); + rcu_read_unlock(); return PTR_ERR(clk); + } + + rcu_read_unlock(); freq = clk_round_rate(clk, target_freq); if ((long)freq <= 0) @@ -605,14 +599,7 @@ int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq) rcu_read_lock(); - opp_table = _find_opp_table(dev); - if (IS_ERR(opp_table)) { - dev_err(dev, "%s: device opp doesn't exist\n", __func__); - rcu_read_unlock(); - 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 +609,7 @@ 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", -- 2.8.1
