[Gta04-owner] Modem off

Dr. H. Nikolaus Schaller hns at goldelico.com
Tue Nov 12 21:04:22 CET 2013


Am 11.11.2013 um 23:49 schrieb NeilBrown:

> On Mon, 11 Nov 2013 16:38:31 +0100 Andreas Kemnade <andreas at kemnade.info>
> wrote:
> 
>>> 
>>> I look forward to hearing of your results.
>> 
>> At the moment I even cannot reproduce your the lower currents when the
>> module is removed or unbind is done (when the modem does not show up on
>> the bus). I measured current_now directly after suspend and retried also
>> with that 5-min average using charge_now.
> 
> What current do you measure? 
> Is it consistent over several measurements?
> What kernel are you using?
> 
>> 
>>> Meanwhile, here is a result that turned out more effective than I expected....
>>> 
>>> I've automated some parts of my power-usage-monitoring a bit more.  With my
>>> phone running normally with USB enabled etc with my current 3.7 kernel, the
>>> average-current-over-5-minutes frequency histogram looks like:
>>> 
>> does this mean, modem shows up on the usb bus during the tests?
> 
> For those tests, yes.  I've done a number of tests with the modem disabled,
> and some with the modem enabled.
> 
> With the modem disable and the ehci-hcd module loaded and unloaded, on a 3.7
> kernel I get 
> 
> 19411 69
> 21567 24
> 43056 1
> 
> With the modem enabled I get
> 
> 23728 44
> 25884 120
> 28057 31
> 30207 6
> 32358 1
> 36684 1
> 51699 1
> 75488 1
> 
> 
> With the pulldown removed I get
> 
> 17251 45

Getting down to 17 mA is already really good. And shows how effective the pull-down-removal is.

> 19410 143
> 21561 36
> 23717 5
> 25888 2
> 30203 2
> 43038 1
> 45527 1
> 49525 1
> 243729 1

Ok, this is quite consistent with a modem that is waking up from time to time and drawing 30-50 mA.
Depending on when you sample you will see all values between.

> 
> 
> And all of these numbers are very close to multiples of 2.15mA.

That may be some effect of the ADC precision.

BR,
Nikolaus


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