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

[Krzysztof Kozlowski <k.kozlowski-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>]

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-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> ---
>  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.

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);
>  
> 

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