[FAQ07421] 待机时,怎么看AP每次wake up起来的时长

970阅读 0评论2014-03-11 ericxlin
分类:Android平台

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FAQ Content

[DESCRIPTION]
分析待机平均电流高的问题时,
经常需要知道每次wake up起来的时间点,以及唤醒的时长,以此找到一些异常的唤醒
 
[SOLUTION]
>>>MT6572
(1)查找kernel log中的“Wakeup Succefully”信息
(2)“往下”查找离这条log最近的带“UTC”的log,UTC log中显示的时间就是唤醒的时间(跟main log的时间一致)
(3)“往下”查找离这条log最近的“[SPM] Kernel Suspend with”信息,跟“Wakeup Succefully”的时间戳相减就是wake up的时长
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eg:
<4>[ 2497.698724]-(0)[789:kworker/u:3][PCM WAKEUP NORMAL]CPU WAKE UP BY: EINT :0x10000
<6>[ 2497.901281] (0)[789:kworker/u:3]PM: suspend exit 2013-05-27 00:40:53.186864384 UTC
<2>[ 2539.341088]-(0)[789:kworker/u:3][SPM] Kernel Suspend with cpu_pdn=1, infra_pdn=1
唤醒时间点:00:40:53
唤醒时长:2539-2497 = 42s
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>>>其他平台
(1)查找kernel log中的“wake up by XXX”信息
(2)“往下”查找离这条log最近的带“UTC”的log,UTC log中显示的时间加8小时就是真实的唤醒时间(跟main log的时间一致)
(3)“往下”查找离这条log最近的“wakesrc”信息,跟“wake up by XXX”的时间戳相减就是wake up的时长
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eg:
<5>[  621.286161] (0)[53:kworker/u:2][Power/Sleep] wake up by EINT (0x20)(0x4)(41695) 
<5>[  621.626419] (0)[310:WindowManagerPo][request_suspend_state]: wakeup (3->0) at 612863283411 (2013-05-24 07:50:14.331687541 UTC)
<5>[  665.287105] (0)[1218:kworker/u:3][Power/Sleep] sec = 300, wakesrc = 0x1ec
 
唤醒时间点:07(+8):50:14 = 15:50:14
唤醒时长:665-621 = 44s
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