On Wed, Apr 26, 2017 at 09:29:18AM +0200, Takashi Iwai wrote: > On Tue, 25 Apr 2017 22:27:19 +0200, > ville.syrjala@xxxxxxxxxxxxxxx wrote: > > > > From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > > > > I was wondering why my VLV no longer runtime suspended, and after some > > thinking I decided it had to be the LPE audio preventing it. Turns out > > I was right, so here's my attempt at fixing it. > > > > And while looking at the code I couldn't help but notice that it > > couldn't actually handle multiple pipes playing back audio at the > > same time. And even having multiple displays active even if only > > one was playing audio was probably a recipe for failure. So I > > tried to fix that by registering a separate PCM device for each > > pipe. > > > > Note that the patch subjects may not reflect the subsystem > > very well since most of these straddle the border between drm > > and alsa. I think I just slapped on drm/i915 to most where > > there was no clear winner. > > A nice patchset, thanks for working on it! > > One slight concern (other than the jack issue Pierre reported) is the > incompatible behavior from the current version. With the pipe-based > multiple streams, user would need to choose another one even if the > device has a single HDMI output, which is pretty common on BYT/CHV > tablets. > > Maybe it's no big problem as the users are still limited at the > moment. Or, we may need to handle a bit differently, e.g. assigning > the PCM stream dynamically per hotplug. Yeah, I tied the PCM device to the pipe to match the hardware. But we could certainly register the PCM device per port, and then do a pipe<->port mapping somewhere to make it all work out. One slight complication is that not all ports are necessarily present so we might have eg. just port B and port D, but no port C. Not sure if it would be a bad thing to register a PCM device even for the missing ports anyway? I don't recall which way HDA works. Device per port I guess? Well, for DP SST/HDMI. But for DP MST I presume it's device per stream (ie. pipe) even with HDA. > In anyway, with the support of multi streams, alsa-lib config needs to > be updated. Hmm. I suppose I'll have to take a gander at what's there. -- Ville Syrjälä Intel OTC _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
