Commit 073d3d2c authored by Viresh Kumar's avatar Viresh Kumar
Browse files

OPP: Level zero is valid 



The level zero can be used by some OPPs to drop performance state vote
for the device. It is perfectly fine to allow the same.

_set_opp_level() considers it as an invalid value currently and returns
early.

In order to support this properly, initialize the level field with
U32_MAX, which denotes unused level field.

Reported-by: default avatarStephan Gerhold <stephan.gerhold@kernkonzept.com>
Reviewed-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
Tested-by: default avatarStephan Gerhold <stephan.gerhold@kernkonzept.com>
Signed-off-by: default avatarViresh Kumar <viresh.kumar@linaro.org>
parent 4c58e9d8

drivers/opp/core.c

+20 −4
Original line number Diff line number Diff line
@@ -201,7 +201,7 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_get_freq_indexed); 
 * @opp:	opp for which level value has to be returned for

 *

 * Return: level read from device tree corresponding to the opp, else

 * return 0.

 * return U32_MAX.

 */

unsigned int dev_pm_opp_get_level(struct dev_pm_opp *opp)

{
@@ -221,7 +221,7 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_get_level); 
 * @index:	index of the required opp

 *

 * Return: performance state read from device tree corresponding to the

 * required opp, else return 0.

 * required opp, else return U32_MAX.

 */

unsigned int dev_pm_opp_get_required_pstate(struct dev_pm_opp *opp,

					    unsigned int index)
@@ -808,6 +808,14 @@ struct dev_pm_opp *dev_pm_opp_find_level_ceil(struct device *dev, 
	struct dev_pm_opp *opp;



	opp = _find_key_ceil(dev, &temp, 0, true, _read_level, NULL);



	/* False match */

	if (temp == OPP_LEVEL_UNSET) {

		dev_err(dev, "%s: OPP levels aren't available\n", __func__);

		dev_pm_opp_put(opp);

		return ERR_PTR(-ENODEV);

	}



	*level = temp;

	return opp;

}
@@ -1049,12 +1057,18 @@ static int _set_opp_bw(const struct opp_table *opp_table, 
static int _set_performance_state(struct device *dev, struct device *pd_dev,

				  struct dev_pm_opp *opp, int i)

{

	unsigned int pstate = likely(opp) ? opp->required_opps[i]->level: 0;

	unsigned int pstate = 0;

	int ret;



	if (!pd_dev)

		return 0;



	if (likely(opp)) {

		pstate = opp->required_opps[i]->level;

		if (pstate == OPP_LEVEL_UNSET)

			return 0;

	}



	ret = dev_pm_domain_set_performance_state(pd_dev, pstate);

	if (ret) {

		dev_err(dev, "Failed to set performance state of %s: %d (%d)\n",
@@ -1135,7 +1149,7 @@ static int _set_opp_level(struct device *dev, struct opp_table *opp_table, 
	int ret = 0;



	if (opp) {

		if (!opp->level)

		if (opp->level == OPP_LEVEL_UNSET)

			return 0;



		level = opp->level;
@@ -1867,6 +1881,8 @@ struct dev_pm_opp *_opp_allocate(struct opp_table *opp_table) 


	INIT_LIST_HEAD(&opp->node);



	opp->level = OPP_LEVEL_UNSET;



	return opp;

}

drivers/opp/of.c

+7 −1
Original line number Diff line number Diff line
@@ -1393,8 +1393,14 @@ int of_get_required_opp_performance_state(struct device_node *np, int index) 


	opp = _find_opp_of_np(opp_table, required_np);

	if (opp) {

		if (opp->level == OPP_LEVEL_UNSET) {

			pr_err("%s: OPP levels aren't available for %pOF\n",

			       __func__, np);

		} else {

			pstate = opp->level;

		}

		dev_pm_opp_put(opp);



	}



	dev_pm_opp_put_opp_table(opp_table);

include/linux/pm_opp.h

+4 −1
Original line number Diff line number Diff line
@@ -92,9 +92,12 @@ struct dev_pm_opp_config { 
	struct device ***virt_devs;

};



#define OPP_LEVEL_UNSET			U32_MAX



/**

 * struct dev_pm_opp_data - The data to use to initialize an OPP.

 * @level: The performance level for the OPP.

 * @level: The performance level for the OPP. Set level to OPP_LEVEL_UNSET if

 * level field isn't used.

 * @freq: The clock rate in Hz for the OPP.

 * @u_volt: The voltage in uV for the OPP.

 */