From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dmitry Osipenko Subject: [PATCH v3 04/16] PM / devfreq: tegra: Don't ignore clk errors Date: Thu, 18 Apr 2019 01:29:13 +0300 Message-ID: <20190417222925.5815-5-digetx@gmail.com> References: <20190417222925.5815-1-digetx@gmail.com> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20190417222925.5815-1-digetx@gmail.com> Sender: linux-kernel-owner@vger.kernel.org To: Thierry Reding , Jonathan Hunter , MyungJoo Ham , Kyungmin Park , Chanwoo Choi , Tomeu Vizoso Cc: linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org List-Id: linux-tegra@vger.kernel.org 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 --- drivers/devfreq/tegra-devfreq.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) diff --git a/drivers/devfreq/tegra-devfreq.c b/drivers/devfreq/tegra-devfreq.c index 7d7b9a5895b2..c7428c5eee23 100644 --- a/drivers/devfreq/tegra-devfreq.c +++ b/drivers/devfreq/tegra-devfreq.c @@ -484,8 +484,10 @@ static int tegra_devfreq_target(struct device *dev, unsigned long *freq, u32 flags) { struct tegra_devfreq *tegra = dev_get_drvdata(dev); + struct devfreq *devfreq = tegra->devfreq; struct dev_pm_opp *opp; unsigned long rate; + int err; opp = devfreq_recommended_opp(dev, freq, flags); if (IS_ERR(opp)) { @@ -495,10 +497,20 @@ 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) + goto restore_min_rate; return 0; + +restore_min_rate: + clk_set_min_rate(tegra->emc_clock, devfreq->previous_freq); + + return err; } static int tegra_devfreq_get_dev_status(struct device *dev, -- 2.21.0