Kindle PW2 battery issues 5.7.2.1

[hardeepthind]

Hello,

I recently upgraded my PW2 (not jailbroken) to the latest firmware 5.7.2.1. Now my battery life has suddenly become quite poor! Has anyone else experienced this?

Being relatively new to kindle/firmware, I looked into downgrading to an earlier version of the firmware but the device doesn't allow that....

Any suggestions or thoughts will be appreciated!

Thanks

[Cinisajoy]

Have you restarted the device?
If not do so now.
Then do a search with random letters to see if it is indexing.

Mine's too, I've restart it and there isn't any index job running.

[HarryT]

Indexing is the usual cause for poor battery life. There's really no reason for a firmware update to affect battery life; the o/s isn't doing any more (or less) than it was before. I installed 5.7.2.1 on my Voyage about two weeks ago, and haven't noticed any change in battery life as a result.

Keeping WiFi turned off will roughly double the battery life of a Kindle. Might you have had it turned off before, but on now?

[NiLuJe]

Some FW updates have been known to scrap the old indexing DB and cause a full reindex, but I'm not sure that was the case here.

[HarryT]

Originally Posted by NiLuJe

Some FW updates have been known to scrap the old indexing DB and cause a full reindex, but I'm not sure that was the case here.

Definitely not the case for me. I upgraded my Voyage from 5.6.5 to 5.7.2.1 and there was no reindexing triggered by the upgrade. Given that I currently have 1866 books on my Voyage (that's a nice improvement in the 5.7.x firmware - it tells you this now), it would have been a huge task to reindex them all.

[knc1]

Originally Posted by HarryT

- - - -
Keeping WiFi turned off will roughly double the battery life of a Kindle. Might you have had it turned off before, but on now?

Everyone was keeping the Kindle in "Airplane Mode" before the jb release and probably not now.

And if the Kindle has 3G + Wifi . . . .
How do you spell battery hog? GSM ?

[loco]

I always keep my kindle pw2 in airplane mode except for once a day for a minute or so when i connect it to wifi and sync between my kindle for android, kindle for pc and my pw2. still my battery life is pathetic. have charged it twice since last morning. i keep it in a case ( the same one that I have been using since the day i bought my kindle) but whenever i open the cover, i am greeted with a battery sign with an exclamation mark saying that i need to recharge my kindle.

i have 186 books on my kindle as on date. I have restarted it twice but the battery woes continue.

PS: i read for 2-3 hours a day on my kindle with 1 hour on low brightness and 1-2 hours while completely lowering the kindle brightness to 0.

PPS: I also searched with random words and there are no indexing jobs running.

[SlashMaster]

I think that I'm experiencing the same issue with my jailbroken KT2. With 5.6.5 (before JB), WiFi on and @30-45' usage per day, the batterry lasted about 3 weeks. After JB about 2 weeks (more apps, more joy). But after a silent OTA update (that I'm starting to regret) and the same usage pattern, the batterry life is only one week (maybe 1.5 with WiFi disabled in stand-by mode). I wonder if 5.7.3 fixes this.

P.S. Is there any Kindle compatible script or app that monitors running programs and estimates battery usage (Android style) ? .. or could I configure the "top" command to log the CPU load ? Thank you!

[knc1]

Originally Posted by SlashMaster

I think that I'm experiencing the same issue with my jailbroken KT2. With 5.6.5 (before JB), WiFi on and @30-45' usage per day, the batterry lasted about 3 weeks. After JB about 2 weeks (more apps, more joy). But after a silent OTA update (that I'm starting to regret) and the same usage pattern, the batterry life is only one week (maybe 1.5 with WiFi disabled in stand-by mode). I wonder if 5.7.3 fixes this.

P.S. Is there any Kindle compatible script or app that monitors running programs and estimates battery usage (Android style) ? .. or could I configure the "top" command to log the CPU load ? Thank you!

The introduction of 5.7.3 so quickly after the most recent firmware release indicates that they are fixing something that went wrong in the earlier builds.

= = = =

As in:
repeat: top -bn1 ?
Plus a bit of simple math.

Embedded systems do not include the documentation man(ual) or info commands.
But full *nix installations and all major web search engines do.

try:
man top
in your favorite search engine.

a snippet of the discription:

The program provides a limited interactive interface for process manipulation as well as a much more extensive interface for personal configuration -- encompassing every aspect of its operation.

Translation: Yes.

[SlashMaster]

Thanks knc1!
If the 5.7.3 update won't fix this issue, I'll try to find the culprit app/process.

[knc1]

Keep in mind, it might be the kernel itself that is the battery hog.
It would be interesting to see what version/build date 5.7.3 is using:

[root@kindle bin]# uname -a
Linux kindle 3.0.35-lab126 #1 PREEMPT Wed Apr 15 08:08:43 PDT 2015 armv7l GNU/Linux

Which is a very early PW-3 (5.6.1.1) build.

And top shows that user 'framework' running 'cvm' is using 98.8% of the cpu - -
With the screen saver showing and supposedly running in the 'low power' state.

I noticed that some time ago but gave it little thought because that device is always on external power.

Hmmm......

[root@kindle bin]# cat /proc/loadavg
1.25 1.30 1.24 3/349 6417

Now that is just wrong for the state it is supposed to be in right now (it should be only active enough to respond to the serial port UART - this isn't my first rodeo).

Note: the first three numbers are what top displays as "Load Adverage:" - which used to be the average number of tasks waiting in the ready queue for three time periods.
At least with the 2.6.x series kernels, I don't know what it is in the 3.0.y series kernels, it may be the price of tea in China.

The mystery deepens:

[root@kindle bin]# cat /proc/softirqs
                    CPU0       
          HI:          0
       TIMER:  175869613
      NET_TX:        254
      NET_RX:       3016
       BLOCK:          0
BLOCK_IOPOLL:          0
     TASKLET:   44937475
       SCHED:          0
     HRTIMER:        376
         RCU:  187274637

[root@kindle bin]# cat /proc/uptime
1837228.26 68387.13 0 0

[root@kindle bin]# cat /sys/power/wakeup_count
0

[root@kindle bin]# cat /sys/power/device_suspend_time_threshold
off

None of that is what I would expect from a device that is 'sleeping' or at least in a heavy dose.

Another change that I just noticed:
/proc/config.gz is enabled in this kernel build (the kernel's build-time configuration file) - Lab126 did not used to do that for us.

Ah, so -

[root@kindle bin]# zcat /proc/config.gz | less

- - - - -
#
# CPU Power Management
#

#
# CPU Frequency scaling
#
- - - - -
# CONFIG_CPU_IDLE is not set
- - - - -

This 5.6.1.1 kernel build will never detect when the cpu is idle.
At least I think that is the situation - I haven't studied kernel config options for a long time.

Edit:
Close:
http://cateee.net/lkddb/web-lkddb/CPU_IDLE.html
And:
http://lists.infradead.org/pipermail...ry/232741.html

Somebody with 5.7.xxx please report the same things I listed above (I included the commands with each).

[SlashMaster]

I updated my KT2 to 5.7.3 last night. Again, (like after the 5.7.2.1 update), I had to re-install USBNetwork package. Also my extra libraries (/lib), custom profile (/etc/profile) and additional user account (/etc/passwd) were lost.


So, here we go (The commands were executed after a reboot):

[root@kindle vasi]# uname -a
Linux kindle 3.0.35-lab126 #1 PREEMPT Fri Feb 26 00:03:50 PST 2016 armv7l GNU/Linux

[root@kindle vasi]# cat /proc/loadavg
1.29 1.02 0.51 2/350 5570

[root@kindle vasi]# cat /proc/softirqs
                    CPU0
          HI:          0
       TIMER:      31235
      NET_TX:          1
      NET_RX:       1458
       BLOCK:          0
BLOCK_IOPOLL:          0
     TASKLET:      51211
       SCHED:          0
     HRTIMER:          3
         RCU:      50075
[root@kindle vasi]# cat /proc/uptime
434.16 103.39 0 0
[root@kindle vasi]# cat /sys/power/wakeup_count
0
[root@kindle vasi]# cat /sys/power/device_suspend_time_threshold
off

#
# CPU Power Management
#

#
# CPU Frequency scaling
#
CONFIG_CPU_FREQ=y
CONFIG_CPU_FREQ_TABLE=y
CONFIG_CPU_FREQ_STAT=y
# CONFIG_CPU_FREQ_STAT_DETAILS is not set
CONFIG_CPU_FREQ_OVERRIDE_LAB126=y
CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE=y
# CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE is not set
# CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE is not set
# CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND is not set
# CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE is not set
# CONFIG_CPU_FREQ_DEFAULT_GOV_INTERACTIVE is not set
CONFIG_CPU_FREQ_GOV_PERFORMANCE=y
CONFIG_CPU_FREQ_GOV_POWERSAVE=y
CONFIG_CPU_FREQ_GOV_USERSPACE=y
CONFIG_CPU_FREQ_GOV_ONDEMAND=y
# CONFIG_CPU_FREQ_GOV_INTERACTIVE is not set
# CONFIG_CPU_FREQ_GOV_CONSERVATIVE is not set
CONFIG_CPU_FREQ_IMX=y
# CONFIG_CPU_IDLE is not set

[knc1]

Yup - they are still having problems with their kernel build (system).

Linux kindle 3.0.35-lab126 #1 PREEMPT Fri Feb 26 00:03:50 PST 2016 armv7l GNU/Linux

They must have some 'new blood' in the kernel build department -
With their own ideas of how things should be done.

Too bad they have not (yet) learned that less than two weeks between build and production release of a kernel is not sufficient time to Q.A. its operation.

Your numbers are smaller only because mine had been 'up' three weeks since the last re-boot.

Would you please post your Kindle's /proc/config.gz file as an attachment please? (see the 'advanced' editor, scroll down below the text box)
No copyright issues, it is GPLv2 just like the kernel.

Note: see below attachment.

[root@kindle root]# cp -a /proc/config.gz /mnt/us/pw3-5.6.1.1-config.gz

[SlashMaster]

Of course I would! Here is my KT2 config.

P.S. So far I do not see any improvements regarding the batterry issue. After 0.5 hours of "activity" (a.k.a restoring the messed by update things, mostly via ssh) and 4 hours of stand-by (screen saver) the batterry is ~ 75%. This sucks!

So, until they fix this I would recommend everyone to stick with 5.6.5 and prevent any OTA update attempts.