[PATCH] UBUNTU: SAUCE: PM: Increase TEST_SUSPEND_SECONDS to avoid false kernel oops on resume

[Stefan Bader]

Andy Whitcroft wrote:
> On Mon, Mar 23, 2009 at 08:43:13AM +0000, TJ wrote:
>> Bug: # 286672
>>
>> This arbitrary value is intended to detect failures during resume.
>>
>> The default value of 5 seconds is however likely to lead to false
>> reports where no failure exists. After analysing all bug reports
>> that had attachments with logs with the string:
>>
>>  "PM: resume devices took XX seconds"
>>
>> It appears there are two ranges of delays to address where no failure
>> occurred:
>>
>> 1. 5-9 seconds: usually just slightly over 5 seconds
>> 2. 10-12 seconds: usually a result of waiting for SATA links
>>
>> Setting TEST_SUSPEND_SECONDS to 12 avoids both of these ranges
>> causing false bug reports.
>> ---
>>  kernel/power/main.c |    2 +-
>>  1 files changed, 1 insertions(+), 1 deletions(-)
>>
>> diff --git a/kernel/power/main.c b/kernel/power/main.c
>> index b8f7ce9..5f73330 100644
>> --- a/kernel/power/main.c
>> +++ b/kernel/power/main.c
>> @@ -144,7 +144,7 @@ static inline int suspend_test(int level) { return 0; }
>>   * The time it takes is system-specific though, so when we test this
>>   * during system bootup we allow a LOT of time.
>>   */
>> -#define TEST_SUSPEND_SECONDS	5
>> +#define TEST_SUSPEND_SECONDS	12
>>  
>>  static unsigned long suspend_test_start_time;
> 
> We are seeing a number of reports triggered by this.  The code talks
> about using a WARN_ON to get the proper focus, but its not clear that it
> achieves that.  Escpecially as this is now going to trigger kerneloops
> I believe.  This does look like a reasonable approach.  I wonder if 12
> is too close to the expected range.  Perhaps 15 or 30 are more reasonable
> places to start producing serious errors.
> 
> -apw
> 
Probably 15. But i guess, whether by kerneloops or not, we probably get the 
bugs reported anyways. Waiting for more than around 5s for resume makes me 
start getting impatient at least.

Stefan

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