Re: [PATCH v4 03/24] PM / devfreq: tegra30: Handle possible round-rate error

[Chanwoo Choi]

On 19. 7. 16. ìí 10:09, Dmitry Osipenko wrote:
> 16.07.2019 14:50, Chanwoo Choi ÐÐÑÐÑ:
>> On 19. 7. 8. ìì 7:32, Dmitry Osipenko wrote:
>>> The EMC clock rate rounding technically could fail, hence let's handle
>>> the error cases properly.
>>>
>>> Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx>
>>> ---
>>>  drivers/devfreq/tegra30-devfreq.c | 17 +++++++++++++++--
>>>  1 file changed, 15 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/drivers/devfreq/tegra30-devfreq.c b/drivers/devfreq/tegra30-devfreq.c
>>> index 5e2b133babdd..5e606ae3f238 100644
>>> --- a/drivers/devfreq/tegra30-devfreq.c
>>> +++ b/drivers/devfreq/tegra30-devfreq.c
>>> @@ -592,8 +592,8 @@ static int tegra_devfreq_probe(struct platform_device *pdev)
>>>  	struct tegra_devfreq_device *dev;
>>>  	struct tegra_devfreq *tegra;
>>>  	struct devfreq *devfreq;
>>> -	unsigned long rate;
>>>  	unsigned int i;
>>> +	long rate;
>>>  	int err;
>>>  
>>>  	tegra = devm_kzalloc(&pdev->dev, sizeof(*tegra), GFP_KERNEL);
>>> @@ -650,8 +650,14 @@ static int tegra_devfreq_probe(struct platform_device *pdev)
>>>  
>>>  	reset_control_deassert(tegra->reset);
>>>  
>>> -	tegra->max_freq = clk_round_rate(tegra->emc_clock, ULONG_MAX) / KHZ;
>>> +	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;
>>> +	}
>>> +
>>>  	tegra->cur_freq = clk_get_rate(tegra->emc_clock) / KHZ;
>>> +	tegra->max_freq = rate / KHZ;
>>>  
>>>  	for (i = 0; i < ARRAY_SIZE(actmon_device_configs); i++) {
>>>  		dev = tegra->devices + i;
>>> @@ -662,6 +668,13 @@ static int tegra_devfreq_probe(struct platform_device *pdev)
>>>  	for (rate = 0; rate <= tegra->max_freq * KHZ; rate++) {
>>>  		rate = clk_round_rate(tegra->emc_clock, rate);
>>>  
>>
>> Please remove unneeded blank line.
> 
> I can remove it, but it was added specifically to ease reading of the code.
> 
>>> +		if (rate < 0) {
>>> +			dev_err(&pdev->dev,
>>> +				"Failed to round clock rate: %ld\n", rate);
>>> +			err = rate;
>>> +			goto remove_opps;
>>> +		}
>>
>> Also, this patch doesn't contain code which restore the previous
>> tegra->cur_freq/max_freq when error happen.
> 
> The error here results in abortion of the driver's probing, hence
> nothing need to be restored in that case because nothing was changed at
> this point yet.
> 
> 

OK.


-- 
Best Regards,
Chanwoo Choi
Samsung Electronics