linux-kernel - [PATCH] opp: fix dev_pm_opp_set_rate for different frequency at the same opp level

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Message-Id: <20210216201030.19152-1-jonathan@marek.ca>
Date:   Tue, 16 Feb 2021 15:10:29 -0500
From:   Jonathan Marek <jonathan@...ek.ca>
To:     linux-arm-msm@...r.kernel.org
Cc:     Viresh Kumar <vireshk@...nel.org>, Nishanth Menon <nm@...com>,
        Stephen Boyd <sboyd@...nel.org>,
        linux-pm@...r.kernel.org (open list:OPERATING PERFORMANCE POINTS (OPP)),
        linux-kernel@...r.kernel.org (open list)
Subject: [PATCH] opp: fix dev_pm_opp_set_rate for different frequency at the same opp level

There is not "nothing to do" when the opp is the same. The frequency can
be different from opp->rate.

Fixes: 81c4d8a3c414 ("opp: Keep track of currently programmed OPP")
Signed-off-by: Jonathan Marek <jonathan@...ek.ca>
---
 drivers/opp/core.c | 7 +++++--
 drivers/opp/opp.h  | 1 +
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/opp/core.c b/drivers/opp/core.c
index c3f3d9249cc5..f82cf72f433e 100644
--- a/drivers/opp/core.c
+++ b/drivers/opp/core.c
@@ -986,6 +986,7 @@ static int _set_opp(struct device *dev, struct opp_table *opp_table,
 		    struct dev_pm_opp *opp, unsigned long freq)
 {
 	struct dev_pm_opp *old_opp;
+	unsigned long old_freq;
 	int scaling_down, ret;
 
 	if (unlikely(!opp))
@@ -996,15 +997,16 @@ static int _set_opp(struct device *dev, struct opp_table *opp_table,
 		_find_current_opp(dev, opp_table);
 
 	old_opp = opp_table->current_opp;
+	old_freq = opp_table->current_freq;
 
 	/* Return early if nothing to do */
-	if (opp_table->enabled && old_opp == opp) {
+	if (opp_table->enabled && old_opp == opp && old_freq == freq) {
 		dev_dbg(dev, "%s: OPPs are same, nothing to do\n", __func__);
 		return 0;
 	}
 
 	dev_dbg(dev, "%s: switching OPP: Freq %lu -> %lu Hz, Level %u -> %u, Bw %u -> %u\n",
-		__func__, old_opp->rate, freq, old_opp->level, opp->level,
+		__func__, old_freq, freq, old_opp->level, opp->level,
 		old_opp->bandwidth ? old_opp->bandwidth[0].peak : 0,
 		opp->bandwidth ? opp->bandwidth[0].peak : 0);
 
@@ -1061,6 +1063,7 @@ static int _set_opp(struct device *dev, struct opp_table *opp_table,
 	/* Make sure current_opp doesn't get freed */
 	dev_pm_opp_get(opp);
 	opp_table->current_opp = opp;
+	opp_table->current_freq = freq;
 
 	return ret;
 }
diff --git a/drivers/opp/opp.h b/drivers/opp/opp.h
index 9b9daf83b074..9f1d9c877380 100644
--- a/drivers/opp/opp.h
+++ b/drivers/opp/opp.h
@@ -186,6 +186,7 @@ struct opp_table {
 	enum opp_table_access shared_opp;
 	struct dev_pm_opp *current_opp;
 	struct dev_pm_opp *suspend_opp;
+	unsigned long current_freq;
 
 	struct mutex genpd_virt_dev_lock;
 	struct device **genpd_virt_devs;
-- 
2.26.1