| Message ID | 20190417222925.5815-5-digetx@gmail.com (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
| Series | NVIDIA Tegra devfreq improvements and Tegra20/30 support | expand |
On 19. 4. 18. 오전 7:29, Dmitry Osipenko wrote: > 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@gmail.com> > --- > 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, > Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
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,
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@gmail.com> --- drivers/devfreq/tegra-devfreq.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-)