Re: [PATCH v2] rtc: s3c: fix disabled clocks for alarm

[Alexandre Belloni <alexandre.belloni@free-electrons.com>]

On 12/08/2015 at 19:21:46 +0900, Joonyoung Shim wrote :
> The clock enable/disable codes for alarm have been removed from
> commit 24e1455493da ("drivers/rtc/rtc-s3c.c: delete duplicate clock
> control") and the clocks are disabled even if alarm is set, so alarm
> interrupt can't happen.
> 
> The s3c_rtc_setaie function can be called several times with 'enabled'
> argument having same value, so it needs to check whether clocks are
> enabled or not.
> 
> Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
> Cc: <stable@vger.kernel.org> # v4.1
> ---
> This is v2 of prior patch "[PATCH 4/4] rtc: s3c: enable/disable clocks
> for alarm".
> 
> Changelog for v2:
> - commit messages is modified by Krzysztof suggestion
> - make to backportable patch
> - add Cc-stable
> 
>  drivers/rtc/rtc-s3c.c | 24 ++++++++++++++++++------
>  1 file changed, 18 insertions(+), 6 deletions(-)
> 

Applied, thanks.

However, ...

> @@ -39,6 +39,7 @@ struct s3c_rtc {
>  	void __iomem *base;
>  	struct clk *rtc_clk;
>  	struct clk *rtc_src_clk;
> +	bool clk_disabled;
>  

This is quite unusual and I would say the principle of least
astonishment would require using clk_enabled and explicitly set it to
true in the probe. I don't expect a lot of changes regarding the clocks
in the probe so this is probably OK but doing so will require extra
carefulness.

-- 
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com