Power management for WIFI component

Embedded Linux Discussions
1

Hi Robert,

The BBBw can put into sleep modes, such as standby, to lower power consumption. I believe it manages power for the components, such as WIFI, Bluetooth, etc. Is the power completely cut off or in low power mode with capability for wake-up for those components?
If those components power is completely cut-off through an external control logic, will those components wake up automatically if CPU wakes up from sleep?

Thank you,
David

2

Hi @dzhou, we never got that fully working for BeagleBoard.org, i ended up disabling the kernel config: CONFIG_CFG80211_DEFAULT_PS:

The Kernel will put the wl18xx into a low power state along with adjusting the sdio bus.

Power won’t just be cut…

Regards,

3

Hi Robert,

Thank you for your input.
I am more concerned with the approach our hardware guys are taking by cutting power to each component using external control logic and expecting those components will magically up running when the CPU wakes up from sleep. I cannot oppose the approach because I am not so sure that cannot be done or very difficult to get it done from software point of view. That is my concern.

Best Regards,
David

4

Well things will be interesting for the wl18xx, as it will require firmware on every power up…

Regards,

5

Hi Robert,

Does waking up from low power mode require to reload the firmware for wl18xx or it only requires firmware if power is completely cut off?

Best Regards,
David

6

If you cut power, the firmware on the wl18xx will have to be reloaded every time power is returned…

Regards,

7

Hi,

Thank you! It is more clear to me now.

Best Regards,
David