Ticket #781 (closed defect: fixed)
LM4857 should be turned off on a reboot notifier
|Reported by:||cesarb@…||Owned by:||willie_chen@…|
|Cc:||buglog@…, cw@…, jserv@…, willie_chen@…||Blocked By:|
|Blocking:||Estimated Completion (week):|
According to http://wiki.openmoko.org/wiki/Neo1973_GTA01_Power_Management, the
LM4857 is connected directly to the battery, and its datasheet shows it uses
several mA when not off. If it is not turned off when shutting down, it will
drain the battery even with the phone off. To avoid this, it should be turned
off when rebooting or powering off the phone.
The best place to turn it off would be by the sound driver in the reboot
notifier chain (register_reboot_notifier). As a workaround, you can set the "Amp
Mode" mixer to "Off" (0) before shutting down the phone.
Thanks to SpeedEvil? for guessing the LM4857 was not being turned off and for
measuring the currents.
comment:10 Changed 6 years ago by laforge@…
- Status changed from assigned to new
- Owner changed from laforge@… to willie_chen@…
comment:21 Changed 6 years ago by laforge@…
- Status changed from assigned to closed
- Resolution set to fixed