Regression on U-boot without batery [was: u-boot low-battery handling]

Andy Green andy at
Tue Aug 26 07:45:35 CEST 2008

Hash: SHA1

Somebody in the thread at some point said:
| Andy Green wrote:
|> Somebody in the thread at some point said:
|> |
|> |
|> | Mike Montour wrote:
|> |> Joerg Reisenweber wrote:
|> |>
|> |>> Powered via  (this particular) 100/500mA USB-Host, none of both
|> |>> U_Boot would boot without battery. Though it's happily working on
|> |>> linux without GSM just on USB-power, after boot with battery.
|> |>
|> |> I have had some success (not all the time) running under Linux with
|> |> USB power and no battery, but I had to turn off the charger through
|> |> "echo 0 > /sys/.../chgmode" as well as turning off GSM.
|> |>
|> |> I have also found that WiFi stops working when the battery is removed,
|> |> but it recovers when I re-insert the battery.
|> |>
|> |
|> | It occurs to me... Is it possible that even with the battery in that we
|> | can get a brownout condition on resume?
|> It's a good thought, but the brownout thing happens really early on
|> startup before the CPU actually comes up.  We definitely get that far.
| Should be able to check easily using a battery simulator, programmable
| power supply, and turning on all the devices. I have gps, gsm,
| accelerometers, the works on when I suspend and can't resume. Most of
| the time I can resume if I leave gsm off.

It'd be funny if the gsm resume issue is merely coming about through
power world.

Of all the things WLAN and GSM are the only ones that take serious
power.  GSM at least is left on, hum.

- -Andy
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