[PATCH 1/1] uboot-pcf50633-default-curr-lim-1A.patch

Andy Green andy at openmoko.com
Thu Feb 21 01:21:17 CET 2008


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Somebody in the thread at some point said:
> Somebody in the thread at some point said:
> 
>>> 1) Stop PMU killing us if we don't have a battery in (by setting default
>>>     current limit to 1A)
> 
>> that this code is _never_ put onto any production / 'sold' devices.  You
>> cannot draw more than 100mA from USB without being configured by the
> 
> Well, it's a good point, but currently we pull more than 100mA just
> waking up from the USB-no-battery case in order to make a negotiation
> for > 100mA... er...

Yeah this is the case, so we can't meet this without doing wakeup
sequencing in a more controlled way and spending time there.

If I leave that limit to 100mA with no battery in the device fails to
start up fully since it needs more than 100mA to get going with LCM up
and trips the limit, causing reboot or shutdown early in U-Boot.  With a
battery in its fine since the battery is leaned on for the balance.

I found it works fine at a 500mA limit which is compatible with overall
USB power availability, so I changed it back to that and will send a
patch for the patch in a moment, thanks for pointing out the badness of
the 1A choice.  For the badness of the 500mA choice, point taken but
this'll do for now until we can actually cope with 100mA limit.

- -Andy
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