Merge tag 'opp-updates-6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/vireshk/pm into pm-opp

Merge OPP updates for v6.10 from Viresh Kumar:

"- Fix required_opp_tables for multiple genpds using same table (Viresh
   Kumar)."

* tag 'opp-updates-6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/vireshk/pm:
  OPP: Fix required_opp_tables for multiple genpds using same table

1 files changed, 30 insertions, 1 deletions

diff --git a/drivers/opp/core.c b/drivers/opp/core.c
index e233734b7220..cb4611fe1b5b 100644
--- a/drivers/opp/core.c
+++ b/drivers/opp/core.c
@@ -2394,7 +2394,8 @@ static void _opp_detach_genpd(struct opp_table *opp_table)
 static int _opp_attach_genpd(struct opp_table *opp_table, struct device *dev,
 			const char * const *names, struct device ***virt_devs)
 {
-	struct device *virt_dev;
+	struct device *virt_dev, *gdev;
+	struct opp_table *genpd_table;
 	int index = 0, ret = -EINVAL;
 	const char * const *name = names;
 
@@ -2428,6 +2429,34 @@ static int _opp_attach_genpd(struct opp_table *opp_table, struct device *dev,
 		}
 
 		/*
+		 * The required_opp_tables parsing is not perfect, as the OPP
+		 * core does the parsing solely based on the DT node pointers.
+		 * The core sets the required_opp_tables entry to the first OPP
+		 * table in the "opp_tables" list, that matches with the node
+		 * pointer.
+		 *
+		 * If the target DT OPP table is used by multiple devices and
+		 * they all create separate instances of 'struct opp_table' from
+		 * it, then it is possible that the required_opp_tables entry
+		 * may be set to the incorrect sibling device.
+		 *
+		 * Cross check it again and fix if required.
+		 */
+		gdev = dev_to_genpd_dev(virt_dev);
+		if (IS_ERR(gdev))
+			return PTR_ERR(gdev);
+
+		genpd_table = _find_opp_table(gdev);
+		if (!IS_ERR(genpd_table)) {
+			if (genpd_table != opp_table->required_opp_tables[index]) {
+				dev_pm_opp_put_opp_table(opp_table->required_opp_tables[index]);
+				opp_table->required_opp_tables[index] = genpd_table;
+			} else {
+				dev_pm_opp_put_opp_table(genpd_table);
+			}
+		}
+
+		/*
 		 * Add the virtual genpd device as a user of the OPP table, so
 		 * we can call dev_pm_opp_set_opp() on it directly.
 		 *