Re: [PATCH 3/7] OPP: Rework _set_required_devs() to manage a single device per call

On 19-06-24, 16:08, Ulf Hansson wrote:

A genpd can have non-genpd devices in the required OPPs and so this
isn't sufficient. What we were ignoring earlier was genpd having
another genpd as required opp.

+		dev_err(dev, "%s: Operation not supported for genpds\n", __func__);
+		return -EOPNOTSUPP;
+	}
 
 	for (i = 0; i < opp_table->required_opp_count; i++) {
-		/* Genpd core takes care of propagation to parent genpd */
-		if (required_devs[i] && opp_table->is_genpd &&
-		    opp_table->required_opp_tables[i]->is_genpd) {
-			dev_err(dev, "%s: Operation not supported for genpds\n", __func__);
-			return -EOPNOTSUPP;
-		}
+		struct opp_table *table = opp_table->required_opp_tables[i];
+
+		/*
+		 * The OPP table should be available at this point. If not, it's
+		 * not the one we are looking for.
+		 */
+		if (IS_ERR(table))
+			continue;
+
+		/* Move to the next available index. */
+		if (opp_table->required_devs[i])
+			continue;
 
-		opp_table->required_devs[i] = required_devs[i];
+		/*
+		 * We need to compare the nodes for the OPP tables, rather than
+		 * the OPP tables themselves, as we may have separate instances.
+		 */
+		if (required_opp_table->np == table->np) {
+

We don't keep such empty lines in OPP core generally at this place.

+			/* Cross check the OPP tables and fix it if needed. */

Copy the bigger comment from_opp_attach_genpd() here too. It helps
understanding why required_opp_tables entry is getting replaced.

+			if (required_opp_table != table) {
+				dev_pm_opp_put_opp_table(table);
+				_get_opp_table_kref(required_opp_table);
+				opp_table->required_opp_tables[i] = required_opp_table;
+			}
+
+			opp_table->required_devs[i] = required_dev;
+
+			/*
+			 * Add the required_dev as a user of the OPP table, so
+			 * we can call dev_pm_opp_set_opp() on it directly.
+			 */
+			if (!_add_opp_dev(required_dev, required_opp_table)) {
+				dev_err(dev, "Failed to add the device to the required OPP table\n");
+				return -ENOMEM;
+			}
+
+			return i;
+		}
 	}

-- 
viresh