linux-kernel - [PATCH] opp: Handle multiple calls for same OPP table in _of_add_opp_table

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:   Tue,  1 Sep 2020 15:57:18 +0530
From:   Viresh Kumar <viresh.kumar@...aro.org>
To:     Viresh Kumar <vireshk@...nel.org>, Nishanth Menon <nm@...com>,
        Stephen Boyd <sboyd@...nel.org>
Cc:     Viresh Kumar <viresh.kumar@...aro.org>, linux-pm@...r.kernel.org,
        Vincent Guittot <vincent.guittot@...aro.org>,
        Rafael Wysocki <rjw@...ysocki.net>, stephan@...hold.net,
        Marek Szyprowski <m.szyprowski@...sung.com>,
        linux-kernel@...r.kernel.org
Subject: [PATCH] opp: Handle multiple calls for same OPP table in _of_add_opp_table_v1()

Until now for V1 OPP bindings we used to call
dev_pm_opp_of_cpumask_add_table() first and then
dev_pm_opp_set_sharing_cpus() in the cpufreq-dt driver.

A later patch will though update the cpufreq-dt driver to optimize the
code a bit and we will call dev_pm_opp_set_sharing_cpus() first followed
by dev_pm_opp_of_cpumask_add_table(), which doesn't work well today as
it tries to re parse the OPP entries. This should work nevertheless for
V1 bindings as the same works for V2 bindings.

Adapt the same approach from V2 bindings and fix this.

Reported-by: Marek Szyprowski <m.szyprowski@...sung.com>
Tested-by: Marek Szyprowski <m.szyprowski@...sung.com>
Signed-off-by: Viresh Kumar <viresh.kumar@...aro.org>
---
 drivers/opp/of.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/drivers/opp/of.c b/drivers/opp/of.c
index d8b623cc015a..6fc56660fa52 100644
--- a/drivers/opp/of.c
+++ b/drivers/opp/of.c
@@ -886,6 +886,16 @@ static int _of_add_opp_table_v1(struct device *dev, struct opp_table *opp_table)
 	const __be32 *val;
 	int nr, ret = 0;
 
+	mutex_lock(&opp_table->lock);
+	if (opp_table->parsed_static_opps) {
+		opp_table->parsed_static_opps++;
+		mutex_unlock(&opp_table->lock);
+		return 0;
+	}
+
+	opp_table->parsed_static_opps = 1;
+	mutex_unlock(&opp_table->lock);
+
 	prop = of_find_property(dev->of_node, "operating-points", NULL);
 	if (!prop)
 		return -ENODEV;
@@ -902,10 +912,6 @@ static int _of_add_opp_table_v1(struct device *dev, struct opp_table *opp_table)
 		return -EINVAL;
 	}
 
-	mutex_lock(&opp_table->lock);
-	opp_table->parsed_static_opps = 1;
-	mutex_unlock(&opp_table->lock);
-
 	val = prop->value;
 	while (nr) {
 		unsigned long freq = be32_to_cpup(val++) * 1000;
-- 
2.25.0.rc1.19.g042ed3e048af