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

Chanwoo Choi
2020-09-15T02:01:19Z

On 9/15/20 11:00 AM, Chanwoo Choi wrote:
> 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

I'm sorry for my typo. s/tree/true.

> 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