[alsa-devel] [PATCH v3 0/5] ALSA: hda - hdmi: ATI/AMD multi-channel and HBR support

[James Le Cuirot]

On Wed, 14 May 2014 13:04:13 +0000
"Deucher, Alexander" <Alexander.Deucher at amd.com> wrote:

> > -----Original Message-----
> > From: Anssi Hannula [mailto:anssi.hannula at iki.fi]
> > Sent: Tuesday, May 13, 2014 5:51 PM
> > To: Deucher, Alexander
> > Cc: James Le Cuirot; alsa-devel at alsa-project.org
> > Subject: Re: [alsa-devel] [PATCH v3 0/5] ALSA: hda - hdmi: ATI/AMD
> > multi- channel and HBR support
> > 
> > Hi Alex,
> > 
> > 14.05.2014 00:10, James Le Cuirot kirjoitti:  
> > > On Tue, 13 May 2014 17:16:17 +0100
> > > James Le Cuirot <chewi at aura-online.co.uk> wrote:
> > >  
> > >> On Tue, 13 May 2014 15:27:47 +0300
> > >> Anssi Hannula <anssi.hannula at iki.fi> wrote:
> > >>  
> > >>> Unfortunately I've been told that HD 4xxx cards and older do not
> > >>> support multichannel playback, which I didn't know at the time
> > >>> (and I had forgotten your case, hence I didn't get back to you
> > >>> - sorry about that).  
> > >>
> > >> Thank you for the quick reply. I'm not sure whether that's
> > >> strictly true. Wikipedia (though not always correct, I grant
> > >> you) states that:
> > >>
> > >> "The RV770 series GPU also supports xvYCC color space output and
> > >> 7.1 surround sound output (LPCM, AC3, DTS) over HDMI."
> > >>
> > >>  
> > http://en.wikipedia.org/wiki/Radeon_HD_4000_Series#Multimedia_feature
> > s  
> > >>
> > >> The HD 4670 has the RV730XT chip. It isn't clear in the above
> > >> statement whether it is referring to the higher models in the
> > >> range or the range as a whole, given that the RV770 is the
> > >> foundation chip. Based on my experiences and what you have
> > >> heard, it's probably the former. This news piece at AnandTech
> > >> also seems to back it up.
> > >>
> > >> "All of AMD's Radeon HD graphics cards have shipped with their
> > >> own audio codec, but the Radeon HD 4800 series of cards finally
> > >> adds support for 8-channel LPCM output over HDMI."
> > >>
> > >> http://www.anandtech.com/show/2556
> > >>
> > >> Looks like a new card for me then. Thanks for your help.  
> > >
> > > Aaaand after all that, I dig out the box for the old card to get
> > > ready to sell it and what do I see printed on the front? 7.1
> > > Channel Sound! The box looks almost identical to this one:
> > >
> > > http://www.overclockers.ua/video/ati-radeon-hd4670-ddr4/01-ati-  
> > radeon-hd4670-sapphire.jpg  
> > >
> > > This is very confusing. Any thoughts?  
> > 
> > Alex, you told me in IRC some time ago that pre-DCE4 cards do no
> > support multi-channel PCM. Do you know what is going on above?
> > AFAIU James has HD 4670, which is RV730 and therefore has DCE3.2
> > only, but seems like it should still have multi-channel support.
> > 
> > Multichannel LPCM support seems to be corroborated by various other
> > sources as well, e.g.
> > http://www.avsforum.com/t/1029603/ati-radeon-hd-4600-4800-series-
> > support-7-1-channel-hdmi-audio#user_ATIHDMIDriver
> > 
> > It doesn't appear to work, though. Is it possible some of those
> > early cards had some other way of getting multichannel LPCM?  
> 
> Does it work with a 3.15 kernel?  It looks like DCE3.1  (RV770) and
> 3.2 (RV7xx) systems may support multichannel LPCM.  IIRC, setting the
> SADs was disabled in older kernels since it seemed to cause problems
> on some systems, but it's been re-enabled in 3.15.

Hi Alex,

If you follow back up this thread, you'll see that I have tried a
recent sound "master" kernel (post 3.15-rc5) and I get this ELD.

https://gist.github.com/chewi/7628058

Also note that I am using the so-called "proprietary" DVI/HDMI adapter,
the HIS HHDMI4071, which I gather is required.

Regards,
James