Just as a followup to the basic power measurement side of this
thread, as opposed to the LCD discussion side, after getting Kevin
Hilman's very latest PM branch, using the omap3_pm_defconfig, changing
from UART1 to UART3 (as instructed), and making the powersave governor
the default, my multimeter now reports 82mA in suspended state. A
pretty decent reduction, in my opinion. For some weird reason, doing
an "echo 149 > export" in the /sys/class/gpio directory no longer
creates a gpio149 interface. All relevant gpio stuff is enabled in
the .config, so this is kind of weird. However, the two LED's
controlled by 149 & 150 seem to be off by default. In arch/arm/mach-
omap2/board-omap3beagle.c I changed the DVI framer to off in the
For those in the know and with the time to answer/comment, a few
1) What is the point of the 'voltage_off_while_idle' control? It
doesn't actually seem to impact anything (no change in current) in
idle mode. If it is enabled and suspend mode is entered, on resume
the board is rebooted. Um, woo? Is that intentional or am I missing
something or doing something wrong?
2) Previously, I got a ton of "failed to enter target state"
messages, which I'm sure explains a lot of the higher observed current
usage, now I'm getting none of these messages. When I look at
pm_debug/count I see a lot of OFF transitions for all power domains,
including core and mpu.
3) Towards the end of the boot process, I see six
"regulator_init_complete: incomplete constraints, leaving X on" for
VDVI, VDAC, VMMC1, VUSB3V1, VUSB1V8, and VUSB1V5. Anything here to be
concerned about? Could I something leave these _off_ and save power
4) Any idea why doing 'echo 149 > export' in the /sys/class/gpio
directory had no effect? That stuff was all enabled by the
omap3_pm_defconfig, so kind of weird there.