On Thu, Feb 25, 2016 at 09:28:59PM +0100, Takashi Iwai wrote:
On Thu, 25 Feb 2016 20:19:08 +0100, Ville Syrjälä wrote:
Hi,
My investigation into some sporadic i915 runtime PM failures seem to point the finger at snd-hda-intel.
I just tried to play around unloding and reloading snd-hda-intel and sometimes I get snd-hda-intel loaded with runtime PM supposedly enabled, but actually the device won't runtime suspend. At which point frobbing with power/control is enough to kick it back into submission.
Which platform are you testing? If it's SKL, BSW or later, multiple codecs are on a single HD-audio bus. In general, you have to adjust the runtime PM of all these codecs in addition to the runtime PM of the controller. Some of them are immediately runtime PM enabled but some of them aren't, left the default as is.
This was on a HSW.
I also have CONFIG_SND_HDA_POWER_SAVE_DEFAULT=1 which I presume should enable codec power saving by deafault?
It might be that your desktop environment adjusts the runtime PM of HD-audio stuff, often depending on the power state. But when you reload, this adjustment is also lost, so you'd have to adjust manually.
There's no desktop environment. Well, unless you count systemd as such. As you can see from the log I included at least the pci device power/control file stayed at 'auto' the whole time until I flipped it to 'on' and then back to 'auto' to fix the problem.
Also the problem didn't happen on every reload AFAICS, so there's something rather non-deterministic happening.