> -----Original Message----- > From: Takashi Iwai [mailto:tiwai@xxxxxxx] > Sent: Wednesday, July 24, 2013 9:43 PM > To: Wang, Xingchao > Cc: Wysocki, Rafael J; David Henningsson; Paulo Zanoni; Daniel Vetter; > daniel.vetter@xxxxxxxx; alsa-devel@xxxxxxxxxxxxxxxx; > intel-gfx@xxxxxxxxxxxxxxxxxxxxx; Girdwood, Liam R; Jin, Gordon > Subject: Re: [alsa-devel] [PATCH 0/4 V7] Power-well API > implementation for Haswell > > At Wed, 24 Jul 2013 13:30:16 +0000, > Wang, Xingchao wrote: > > > > > > > > > -----Original Message----- > > > From: Wysocki, Rafael J > > > Sent: Wednesday, July 24, 2013 9:15 PM > > > To: David Henningsson > > > Cc: Wang, Xingchao; Takashi Iwai; Paulo Zanoni; Daniel Vetter; > > > daniel.vetter@xxxxxxxx; alsa-devel@xxxxxxxxxxxxxxxx; > > > intel-gfx@xxxxxxxxxxxxxxxxxxxxx; Girdwood, Liam R; Jin, Gordon > > > Subject: Re: [alsa-devel] [PATCH 0/4 V7] Power-well API > > > implementation for Haswell > > > > > > On 7/24/2013 1:57 PM, David Henningsson wrote: > > > > On 07/24/2013 01:33 PM, Wang, Xingchao wrote: > > > >> Yes, I agree. I'm debugging this issue on Ubuntu, not sure it > > > >> happens on other distribution too. > > > >> If it's related to Ubuntu, maybe need check Ubuntu power policy. > > > >> Does anyone know the Ubuntu power-policy on laptop? > > > >> i.e. when charger connected, will Ubuntu make decision to disable > > > >> power-save feature for audio subsystem? > > > > > > > > I'm not a power management expert, but I got a pointer from my > > > > team mate to pm-utils: > > > > > > > > http://cgit.freedesktop.org/pm-utils/tree/pm/power.d/intel-audio-p > > > > ower > > > > save > > > > > > > > > > > > If I understand correctly, The scripts in power.d are executed > > > > when battery / AC-power is changed. > > > > > > > > > > To me, this sounds like a user space issue. It requested power on > > > and the kernel delivered. > > > > Do you know which user-space application will touch below two flags? > > - /sys/devices/pci0000\:00/0000\:00\:03.0/power/control > > - /sys/module/snd_hda_intel/parameters/power_save > > The latter is touched most likely by pm-utils, one of the hooks, as David pointed. > The former is unknown, but better to check pm-utils hooks and udev rules. > Okay, thank you all for pointing out to the right direction. I'm checking the pm-utils mentioned from David. :) Thanks --xingchao > > Takashi _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
