Messages in this thread | | | Subject | Re: [PATCH v1 4/4] PM / devfreq: tegra30: Check whether clk_round_rate() returns zero rate | From | Chanwoo Choi <> | Date | Sun, 19 Sep 2021 18:43:41 +0900 |
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On 21. 9. 16. 오전 10:28, Dmitry Osipenko wrote: > 15.09.2021 21:31, Chanwoo Choi пишет: >> On 21. 9. 15. 오후 12:51, Chanwoo Choi wrote: >>> Hi, >>> >>> On 21. 9. 13. 오전 3:44, Dmitry Osipenko wrote: >>>> EMC clock is always-on and can't be zero. Check whether clk_round_rate() >>>> returns zero rate and error out if it does. It can return zero if clock >>>> tree isn't initialized properly. >>>> >>>> Signed-off-by: Dmitry Osipenko <digetx@gmail.com> >>>> --- >>>> drivers/devfreq/tegra30-devfreq.c | 4 ++-- >>>> 1 file changed, 2 insertions(+), 2 deletions(-) >>>> >>>> diff --git a/drivers/devfreq/tegra30-devfreq.c >>>> b/drivers/devfreq/tegra30-devfreq.c >>>> index d83fdc2713ed..65ecf17a36f4 100644 >>>> --- a/drivers/devfreq/tegra30-devfreq.c >>>> +++ b/drivers/devfreq/tegra30-devfreq.c >>>> @@ -891,9 +891,9 @@ static int tegra_devfreq_probe(struct >>>> platform_device *pdev) >>>> return err; >>>> rate = clk_round_rate(tegra->emc_clock, ULONG_MAX); >>>> - if (rate < 0) { >>>> + if (rate <= 0) { >>>> dev_err(&pdev->dev, "Failed to round clock rate: %ld\n", >>>> rate); >>>> - return rate; >>>> + return rate ?: -EINVAL; >> >> If rate is 0, It doesn't return and fall-through? even if print the >> error message. 'return rate ?: -EINVAL;' style is strange for me >> because it doesn't specify the 'return value' when rate is true. > > It's not clear to me what do you mean by "return and fall-through". > > It specifies the 'return value' when rate is true. It's a short form of > "rate ? rate : -EINVAL".
I has not known this short form. Thanks for comment. I understand.
-- Best Regards, Samsung Electronics Chanwoo Choi
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