Re: [PATCH 3/3] spi: s3c64xx: simplify suspend/resume handlers

[Heiner Kallweit <hkallweit1@gmail.com>]

Am 19.08.2015 um 03:11 schrieb Krzysztof Kozlowski:
> On 19.08.2015 06:08, Heiner Kallweit wrote:
>> The runtime PM handlers take care of enabling / disabling the clock.
>> Therefore use them to simplify the suspend / resume handlers.
>>
>> pm_runtime_suspend/resume internally check whether suspending/resuming
>> is possible and return 1 in case PM state is suspended/active already.
>>
>> Currently there also seems to be a bug in the resume handler
>> as suspend as well as resume check for !pm_runtime_disabled(dev).
> 
> Actually currently there is a bug because PM runtime is not disabled and
> concurrent runtime suspends/resumes can happen.
> 
>>
>> Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
>> ---
>>  drivers/spi/spi-s3c64xx.c | 15 +++++++--------
>>  1 file changed, 7 insertions(+), 8 deletions(-)
>>
>> diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
>> index 15a6de1..78a6f04 100644
>> --- a/drivers/spi/spi-s3c64xx.c
>> +++ b/drivers/spi/spi-s3c64xx.c
>> @@ -1242,10 +1242,9 @@ static int s3c64xx_spi_suspend(struct device *dev)
>>  	if (ret)
>>  		return ret;
>>  
>> -	if (!pm_runtime_suspended(dev)) {
>> -		clk_disable_unprepare(sdd->clk);
>> -		clk_disable_unprepare(sdd->src_clk);
>> -	}
>> +	ret = pm_runtime_suspend(dev);
> 
> I think you need pm_runtime_force_suspend() instead. Same for resume.
You're right. Will update the patch.

Regards, Heiner
> 
> Best regards,
> Krzysztof
> 
>> +	if (ret < 0)
>> +		return ret;
>>  
>>  	sdd->cur_speed = 0; /* Output Clock is stopped */
>>  
>> @@ -1257,14 +1256,14 @@ static int s3c64xx_spi_resume(struct device *dev)
>>  	struct spi_master *master = dev_get_drvdata(dev);
>>  	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
>>  	struct s3c64xx_spi_info *sci = sdd->cntrlr_info;
>> +	int ret;
>>  
>>  	if (sci->cfg_gpio)
>>  		sci->cfg_gpio();
>>  
>> -	if (!pm_runtime_suspended(dev)) {
>> -		clk_prepare_enable(sdd->src_clk);
>> -		clk_prepare_enable(sdd->clk);
>> -	}
>> +	ret = pm_runtime_resume(dev);
>> +	if (ret < 0)
>> +		return ret;
>>  
>>  	s3c64xx_spi_hwinit(sdd, sdd->port_id);
>>  
>>
> 
>