linux-kernel - Re: [RFC PATCH 1/2] rtc: s3c: Remove unnecessary call to disable already disabled clock

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Message-id: <577B74E8.3010208@samsung.com>
Date:	Tue, 05 Jul 2016 10:50:48 +0200
From:	Krzysztof Kozlowski <k.kozlowski@...sung.com>
To:	Alim Akhtar <alim.akhtar@...sung.com>, rtc-linux@...glegroups.com,
	linux-kernel@...r.kernel.org
Cc:	alexandre.belloni@...e-electrons.com, javier@....samsung.com,
	pankaj.dubey@...sung.com
Subject: Re: [RFC PATCH 1/2] rtc: s3c: Remove unnecessary call to disable
 already disabled clock

On 07/05/2016 10:46 AM, Alim Akhtar wrote:
> Hi Krzsztof,
> 
> On 07/05/2016 12:48 PM, Krzysztof Kozlowski wrote:
>> On 07/04/2016 01:03 PM, Alim Akhtar wrote:
>>> At the end of s3c_rtc_probe(), s3c_rtc_disable_clk() being called
>>> with rtc
>>> clock already disabled, which looks extra and unnecessary call.
>>> Lets clean it up.
>>
>> Does not look right. Till that place, the clocks are enabled. Then
>> s3c_rtc_setaie() is called which expects that clocks are disabled...
>> otherwise counters get mixed.
>>
> 
> The clock is always disabled when it reach s3c_rtc_setfreq() in probe(),
> because s3c_rtc_gettime() will always disable the clock.
> 
> As far as s3c_rtc_setaie() is concern, it enables clock while entering
> and disables it while leaving the function. And in
> s3c_rtc_{enable,disable}_clk() there is check info->clk_disabled flag
> which will make sure clock balancing.

Ah, you're right. Looks correct although the information that clock is
disabled because of s3c_rtc_gettime() would be useful in the commit message.

Reviewed-by: Krzysztof Kozlowski <k.kozlowski@...sung.com>

Best regards,
Krzysztof