Management of Power Management ;)
ben at abcom.co.nz
Sat Aug 22 15:24:29 CEST 2009
Paul Fertser wrote:
> On Fri, Aug 21, 2009 at 07:17:12PM -0700, Svetoslav Trochev wrote:
>> Paul Fertser wrote:
>>> BTW, for a start you can fix SD power control issues (due to a bad
>>> merge the function got fubarred), if you run with SD inserted you'll
>>> have extra ~20mA feeding card even in suspend.
>> Today I have build my self a current probe for my Neo1973 and did some
>> measurements. Here are my results
>> 1. Bootloader (splash screen): 0.30-0.32A
>> 2. Kernel loads: 0.22-0.28A
>> 3. SHR loaded and GSM registered to the network: 0.26A and 0.28A if I
>> have uSD card inserted.
>> 4. SHR with LED backlight off: 0.18A and 0.19-0.20A with uSD
> This all corresponds with what i heard about the device so far.
>> 5. SHR suspend, GSM on: 0.08A
> This one looks strange, guys measured it to be ~45mA with uSD inserted and
> ~25mA without.
I measured ~45 / ~25mA most of the time but on two occasions I did see
~75mA, i couldn't reproduce it though.
You do see some weird things current wise when gsm is on during suspend.
>> 6. Neo1973 shutdown from SHR power menu: 0.03A (BAD. I thing the GSM is
>> still on)
> Yes, it's still on, known problem. We're waiting for Mickey's fix. The
> problem is that frameworkd "forgets" to turn the modem off (gta02 has a
> hardware switch but for gta01 software needs to write AT at POFF several times
> to reliably turn the modem off). And it still looks too much, the expected
> modem current is about 8mA.
>> The max charging current I measured is 0.32A with 50% discharged battery
>> and SHR in suspend mode.
> Considering the limit is 500mA and suspend current according to your
> measurements is 0.08, it looks like 100mA went nowhere. Weird.
>> The charge current after I disconnected the battery for 20s is as
>> expected 0.10A. One problem I notice is that u-boot 1.3.1 will power on
>> the phone as soon the battery voltage rises. So if you have dippy
>> discharged battery the boot might fail and device will hang and draw
>> residual current and it will drain the battery even dipper. I believe
>> the old u-boot never powered on the phone automatically.
> It's supposed that all charging should be done with Linux running, at least
> that was the general idea at the time of development. The system should
> ensure that it will never discharge the battery too much. Well, easier said
> than done.
> BTW, _never_ever_ take out the battery from gta01 running on USB power. It
> will destroy it for sure if you don't pull of the cord immediately.
>> this problems. I will need some help setting up my development
>> environment. Currently I am running Ubuntu 8.04LTS.
> For kernel hacking all you need is compiler, git and text editor. So, i'd
> recommend to install emdebian (i think ubuntu is compatible with it), with
> the help of emdebian install the toolchain, then git clone the sources from
> git.openmoko.org and start hacking.
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