linux-kernel - [PATCH v2 03/19] PM / devfreq: tegra: Don't ignore clk errors

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Date:   Mon, 15 Apr 2019 17:54:49 +0300
From:   Dmitry Osipenko <digetx@...il.com>
To:     Thierry Reding <thierry.reding@...il.com>,
        Jonathan Hunter <jonathanh@...dia.com>,
        MyungJoo Ham <myungjoo.ham@...sung.com>,
        Kyungmin Park <kyungmin.park@...sung.com>,
        Chanwoo Choi <cw00.choi@...sung.com>,
        Tomeu Vizoso <tomeu.vizoso@...labora.com>
Cc:     linux-tegra@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-pm@...r.kernel.org
Subject: [PATCH v2 03/19] PM / devfreq: tegra: Don't ignore clk errors

The clk_set_min_rate() could fail and in this case clk_set_rate() sets
rate to 0, which may drop EMC rate to minimum and make machine very
difficult to use.

Signed-off-by: Dmitry Osipenko <digetx@...il.com>
---
 drivers/devfreq/tegra-devfreq.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/devfreq/tegra-devfreq.c b/drivers/devfreq/tegra-devfreq.c
index 0c0909fba545..69581c9082d4 100644
--- a/drivers/devfreq/tegra-devfreq.c
+++ b/drivers/devfreq/tegra-devfreq.c
@@ -487,6 +487,7 @@ static int tegra_devfreq_target(struct device *dev, unsigned long *freq,
 	struct tegra_devfreq *tegra = dev_get_drvdata(dev);
 	struct dev_pm_opp *opp;
 	unsigned long rate;
+	int err;
 
 	opp = devfreq_recommended_opp(dev, freq, flags);
 	if (IS_ERR(opp)) {
@@ -496,8 +497,13 @@ static int tegra_devfreq_target(struct device *dev, unsigned long *freq,
 	rate = dev_pm_opp_get_freq(opp);
 	dev_pm_opp_put(opp);
 
-	clk_set_min_rate(tegra->emc_clock, rate);
-	clk_set_rate(tegra->emc_clock, 0);
+	err = clk_set_min_rate(tegra->emc_clock, rate);
+	if (err)
+		return err;
+
+	err = clk_set_rate(tegra->emc_clock, 0);
+	if (err)
+		return err;
 
 	return 0;
 }
-- 
2.21.0