I’ve got a bit of a problem with my Wifi card, which uses a Broadcom chipset [14e4:4727]. I have a HP Probook 4520s. While on AC power, everything works fine, but whenever it switches to battery, the Wifi stops working.
I thought that it was a power management related issue, so I disabled WiFi power management in laptop-mode. Even that didn’t solve the problem. But, using
iwconfig eth1 power off
fixes the problem. While this setting holds while the AC power is plugged in, whenever the laptop switches to battery power, the Power mode reverts back to all (all packets received). This results in the Wifi not working until I use the command
iwconfig eth1 power off
again.
I have looked in many places, even Googled to find out which module controls power management for the Wifi card, but have found no clues. I’d love to know exactly which module controls the switching of the Wifi power mode and how to disable it.