[PATCH] time: Fix sleeptime injection for non-stop clocksource & persistent clock

[PATCH] time: Fix sleeptime injection for non-stop clocksource & persistent clock

[Mukesh Ojha]

Currently, for both non-stop clocksource and persistent clock
there is a corner case, when a driver failed to go suspend mode
rtc_resume injects the sleeptime as timekeeping_rtc_skipresume
returned 'false' due to which we can see mismatch in time with
system clock.

Success case:
                                         {sleeptime_injected=true}
rtc_suspend() => timekeeping_suspend() => timekeeping_resume() => rtc_resume()

Failure case:
             {failure in sleep path} {sleeptime_injected=false}
rtc_suspend()       =>             rtc_resume()

Change-Id: I98928761c98cec21a3033a55d3e10fb34138f38c
Signed-off-by: Mukesh Ojha <mojha@codeaurora.org>
---
 kernel/time/timekeeping.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 427e33d..c022d82 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -1511,9 +1511,6 @@ void __weak read_boot_clock64(struct timespec64 *ts)
 	ts->tv_nsec = 0;
 }
 
-/* Flag for if timekeeping_resume() has injected sleeptime */
-static bool sleeptime_injected;
-
 /* Flag for if there is a persistent clock on this platform */
 static bool persistent_clock_exists;
 
@@ -1611,7 +1608,14 @@ static void __timekeeping_inject_sleeptime(struct timekeeper *tk,
  */
 bool timekeeping_rtc_skipresume(void)
 {
-	return sleeptime_injected;
+	struct timekeeper *tk = &tk_core.timekeeper;
+	bool skip_rtc_resume = false;
+
+	skip_rtc_resume = ((tk->tkr_mono.clock->flags &
+			CLOCK_SOURCE_SUSPEND_NONSTOP) ||
+			(persistent_clock_exists)) ? true : false;
+
+	return skip_rtc_resume;
 }
 
 /**
@@ -1671,8 +1675,8 @@ void timekeeping_resume(void)
 	unsigned long flags;
 	struct timespec64 ts_new, ts_delta;
 	cycle_t cycle_now, cycle_delta;
+	bool sleeptime_injected = false;
 
-	sleeptime_injected = false;
 	read_persistent_clock64(&ts_new);
 
 	clockevents_resume();
-- 
Qualcomm India Private Limited, on behalf of Qualcomm Innovation Center,
Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project

Re: [PATCH] time: Fix sleeptime injection for non-stop clocksource & persistent clock

[Vinod Koul]

On 29-05-18, 13:45, Mukesh Ojha wrote:
> Currently, for both non-stop clocksource and persistent clock
> there is a corner case, when a driver failed to go suspend mode
> rtc_resume injects the sleeptime as timekeeping_rtc_skipresume
> returned 'false' due to which we can see mismatch in time with
> system clock.
> 
> Success case:
>                                          {sleeptime_injected=true}
> rtc_suspend() => timekeeping_suspend() => timekeeping_resume() => rtc_resume()
> 
> Failure case:
>              {failure in sleep path} {sleeptime_injected=false}
> rtc_suspend()       =>             rtc_resume()
> 
> Change-Id: I98928761c98cec21a3033a55d3e10fb34138f38c

This does not belong in upstream please remove. I think checkpatch warns.

Also I see that you have sent to lkml and arm-msm mailing list, but have not
CCed any maintainers. Please run ./scripts/get_maintainer.pl to find who to send
patches to. Chances are it will get ignored...

> Signed-off-by: Mukesh Ojha <mojha@codeaurora.org>
> ---
>  kernel/time/timekeeping.c | 14 +++++++++-----
>  1 file changed, 9 insertions(+), 5 deletions(-)
> 
> diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
> index 427e33d..c022d82 100644
> --- a/kernel/time/timekeeping.c
> +++ b/kernel/time/timekeeping.c
> @@ -1511,9 +1511,6 @@ void __weak read_boot_clock64(struct timespec64 *ts)
>  	ts->tv_nsec = 0;
>  }
>  
> -/* Flag for if timekeeping_resume() has injected sleeptime */
> -static bool sleeptime_injected;
> -
>  /* Flag for if there is a persistent clock on this platform */
>  static bool persistent_clock_exists;
>  
> @@ -1611,7 +1608,14 @@ static void __timekeeping_inject_sleeptime(struct timekeeper *tk,
>   */
>  bool timekeeping_rtc_skipresume(void)
>  {
> -	return sleeptime_injected;
> +	struct timekeeper *tk = &tk_core.timekeeper;
> +	bool skip_rtc_resume = false;
> +
> +	skip_rtc_resume = ((tk->tkr_mono.clock->flags &
> +			CLOCK_SOURCE_SUSPEND_NONSTOP) ||
> +			(persistent_clock_exists)) ? true : false;
> +
> +	return skip_rtc_resume;
>  }
>  
>  /**
> @@ -1671,8 +1675,8 @@ void timekeeping_resume(void)
>  	unsigned long flags;
>  	struct timespec64 ts_new, ts_delta;
>  	cycle_t cycle_now, cycle_delta;
> +	bool sleeptime_injected = false;
>  
> -	sleeptime_injected = false;
>  	read_persistent_clock64(&ts_new);
>  
>  	clockevents_resume();
> -- 
> Qualcomm India Private Limited, on behalf of Qualcomm Innovation Center,
> Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

-- 
~Vinod

Re: [PATCH] time: Fix sleeptime injection for non-stop clocksource & persistent clock

[Mukesh Ojha]

On 5/29/2018 2:18 PM, Vinod Koul wrote:
> On 29-05-18, 13:45, Mukesh Ojha wrote:
>> Currently, for both non-stop clocksource and persistent clock
>> there is a corner case, when a driver failed to go suspend mode
>> rtc_resume injects the sleeptime as timekeeping_rtc_skipresume
>> returned 'false' due to which we can see mismatch in time with
>> system clock.
>>
>> Success case:
>>                                           {sleeptime_injected=true}
>> rtc_suspend() => timekeeping_suspend() => timekeeping_resume() => rtc_resume()
>>
>> Failure case:
>>               {failure in sleep path} {sleeptime_injected=false}
>> rtc_suspend()       =>             rtc_resume()
>>
>> Change-Id: I98928761c98cec21a3033a55d3e10fb34138f38c
> This does not belong in upstream please remove. I think checkpatch warns.
>
> Also I see that you have sent to lkml and arm-msm mailing list, but have not
> CCed any maintainers. Please run ./scripts/get_maintainer.pl to find who to send
> patches to. Chances are it will get ignored...

Thanks Vinod.
Will resend it after including maintainers.

-Mukesh
>
>> Signed-off-by: Mukesh Ojha <mojha@codeaurora.org>
>> ---
>>   kernel/time/timekeeping.c | 14 +++++++++-----
>>   1 file changed, 9 insertions(+), 5 deletions(-)
>>
>> diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
>> index 427e33d..c022d82 100644
>> --- a/kernel/time/timekeeping.c
>> +++ b/kernel/time/timekeeping.c
>> @@ -1511,9 +1511,6 @@ void __weak read_boot_clock64(struct timespec64 *ts)
>>   	ts->tv_nsec = 0;
>>   }
>>   
>> -/* Flag for if timekeeping_resume() has injected sleeptime */
>> -static bool sleeptime_injected;
>> -
>>   /* Flag for if there is a persistent clock on this platform */
>>   static bool persistent_clock_exists;
>>   
>> @@ -1611,7 +1608,14 @@ static void __timekeeping_inject_sleeptime(struct timekeeper *tk,
>>    */
>>   bool timekeeping_rtc_skipresume(void)
>>   {
>> -	return sleeptime_injected;
>> +	struct timekeeper *tk = &tk_core.timekeeper;
>> +	bool skip_rtc_resume = false;
>> +
>> +	skip_rtc_resume = ((tk->tkr_mono.clock->flags &
>> +			CLOCK_SOURCE_SUSPEND_NONSTOP) ||
>> +			(persistent_clock_exists)) ? true : false;
>> +
>> +	return skip_rtc_resume;
>>   }
>>   
>>   /**
>> @@ -1671,8 +1675,8 @@ void timekeeping_resume(void)
>>   	unsigned long flags;
>>   	struct timespec64 ts_new, ts_delta;
>>   	cycle_t cycle_now, cycle_delta;
>> +	bool sleeptime_injected = false;
>>   
>> -	sleeptime_injected = false;
>>   	read_persistent_clock64(&ts_new);
>>   
>>   	clockevents_resume();
>> -- 
>> Qualcomm India Private Limited, on behalf of Qualcomm Innovation Center,
>> Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html