At Wed, 18 Mar 2015 20:34:34 +0100, David Henningsson wrote:
On 2015-03-18 09:50, Takashi Iwai wrote:
Hi,
here is a patchset for supporting more aggressive PM for HD-audio. This allows to change the power state of each widget more dynamically with jack and stream states. It's activated only when the codec driver (or via sysfs or f/w patch) sets codec->power_mgmt flag.
Cool. Could you elaborate on how the power_mgmt flag interacts with the power_save module parameter (which, on Ubuntu, is set dynamically based on AC power or not)? I e, does it make sense to test this both with and without power_save enabled?
Also I assume power_save_controller should not matter, right?
The new stuff basically works independently from traditional power_save and power_save_controller options. But, you can think it's on top of power_save stuff, i.e. trying to power on/off of each widget in the codec while the codec itself is powered on by power_save.
Hierarchy is something like: power_mgmt (managing D0/D3 of each codec widget) --> power_save (managing D0/D3 of FG node of the codec) --> power_save_controller (managing D0/D3 of HDA controller)
Takashi