Hi,
On 19. 4. 15. 오후 11:54, 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@xxxxxxxxx>
> ---
> 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)
Why don't you restore the previous minimum clock for tegra->emc_clock
when failed to execute 'clk_set_rate(tegra->emc_clock, 0);'?
I think that if you control the restoring the previous minimum clock,
it is more nice to handle the error handling.
> + return err;
>
> return 0;
> }
>
--
Best Regards,
Chanwoo Choi
Samsung Electronics
