Re: [PATCH V4 06/10] PM / OPP: Add infrastructure to manage multiple regulators

On 11/24, Viresh Kumar wrote:

diff --git a/drivers/base/power/opp/core.c b/drivers/base/power/opp/core.c index 37fad2eb0f47..2d5c726c920f 100644 --- a/drivers/base/power/opp/core.c +++ b/drivers/base/power/opp/core.c @@ -235,21 +240,41 @@ unsigned long dev_pm_opp_get_max_volt_latency(struct device *dev) return 0; }

• reg = opp_table->regulator;
• if (IS_ERR(reg)) {

• count = opp_table->regulator_count;
• if (!count) { /* Regulator may not be required for device */ rcu_read_unlock(); return 0; }

• list_for_each_entry_rcu(opp, &opp_table->opp_list, node) {

• if (!opp->available)
  

• 	continue;
  

• size = count * sizeof(*regulators);
• regulators = kmemdup(opp_table->regulators, size, GFP_KERNEL);

Again, can't allocate with sleeping calls under RCU read lock as it may have disabled preemption.

• if (!regulators) {

• rcu_read_unlock();
  

• return 0;
  

• }
• uV = kmalloc_array(count, sizeof(*uV), GFP_KERNEL);
• if (!uV) {

• kfree(regulators);
  

• rcu_read_unlock();
  

• return 0;
  

• }

• if (opp->supply.u_volt_min < min_uV)
  

• 	min_uV = opp->supply.u_volt_min;
  

• if (opp->supply.u_volt_max > max_uV)
  

• 	max_uV = opp->supply.u_volt_max;
  

• for (i = 0; i < count; i++) {

• uV[i].min = ~0;
  

• uV[i].max = 0;
  

• list_for_each_entry_rcu(opp, &opp_table->opp_list, node) {
  

• 	if (!opp->available)
  

• 		continue;
  

• 	if (opp->supplies[i].u_volt_min < uV[i].min)
  

• 		uV[i].min = opp->supplies[i].u_volt_min;
  

• 	if (opp->supplies[i].u_volt_max > uV[i].max)
  

• 		uV[i].max = opp->supplies[i].u_volt_max;
  

• }
  

  }

rcu_read_unlock(); @@ -924,35 +960,50 @@ struct dev_pm_opp *_allocate_opp(struct device *dev, struct opp_table **opp_table) { struct dev_pm_opp *opp;

• int count, supply_size;
• struct opp_table *table;

• /* allocate new OPP node */
• opp = kzalloc(sizeof(*opp), GFP_KERNEL);
• if (!opp)

• table = _add_opp_table(dev);
• if (!table) return NULL;

• INIT_LIST_HEAD(&opp->node);

• /* Allocate space for at least one supply */
• count = table->regulator_count ? table->regulator_count : 1;
• supply_size = sizeof(*opp->supplies) * count;

• *opp_table = _add_opp_table(dev);
• if (!*opp_table) {

• kfree(opp);
  

• /* allocate new OPP node + and supplies structures */

s/+//

• opp = kzalloc(sizeof(*opp) + supply_size, GFP_KERNEL);
• if (!opp) {

• kfree(table);
  

  return NULL; }