Re: [PATCH] PM / devfreq: tegra30: disable clock on error in probe

Chanwoo Choi
2020-09-15T01:48:47Z

Hi Dmitry,

On 9/14/20 10:56 PM, Dmitry Osipenko wrote:
> 14.09.2020 10:09, Chanwoo Choi пишет:
>> Hi,
>>
>> On 9/8/20 4:25 PM, Dan Carpenter wrote:
>>> This error path needs to call clk_disable_unprepare().
>>>
>>> Fixes: 7296443b900e ("PM / devfreq: tegra30: Handle possible round-rate error")
>>> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
>>> ---
>>> ---
>>> drivers/devfreq/tegra30-devfreq.c | 4 +++-
>>> 1 file changed, 3 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/devfreq/tegra30-devfreq.c b/drivers/devfreq/tegra30-devfreq.c
>>> index e94a27804c20..dedd39de7367 100644
>>> --- a/drivers/devfreq/tegra30-devfreq.c
>>> +++ b/drivers/devfreq/tegra30-devfreq.c
>>> @@ -836,7 +836,8 @@ static int tegra_devfreq_probe(struct platform_device *pdev)
>>> rate = clk_round_rate(tegra->emc_clock, ULONG_MAX);
>>> if (rate < 0) {
>>> dev_err(&pdev->dev, "Failed to round clock rate: %ld\n", rate);
>>> - return rate;
>>> + err = rate;
>>> + goto disable_clk;
>>> }
>>>
>>> tegra->max_freq = rate / KHZ;
>>> @@ -897,6 +898,7 @@ static int tegra_devfreq_probe(struct platform_device *pdev)
>>> dev_pm_opp_remove_all_dynamic(&pdev->dev);
>>>
>>> reset_control_reset(tegra->reset);
>>> +disable_clk:
>>> clk_disable_unprepare(tegra->clock);
>>
>> Is it doesn't need to reset with reset_contrl_reset()?
>
> Hello, Chanwoo!
>
> It's reset just before the clk_round_rate() invocation, hence there
> shouldn't be a need to reset it second time.

Do you mean that reset is deasserted automatically
when invoke clk_round_rate() on tegra?

If tree, I think that 'reset_control_reset(tegra->reset)' invocation
is not needed on 'remove_opp:' goto. Because already reset deassertion
is invoked by clk_round_rate(), it seems that doesn't need to invoke
anymore during exception case.

Actually, it is not clear in my case.

--
Best Regards,
Chanwoo Choi
Samsung Electronics