Which Nvidia IGPs support 7.1 channel LPCM under Linux?

[nvtux]

Hi,

I am planning to build a linux workstation or two that have both advanced scientific computing (via CUDA and Stream) as well as multimedia/HTPC/gaming capabilities. Towards that end, for starters, I am trying to figure out (with some certitude) as to which of Nvidia's IGPs listed below (taken from this HTPC building guide) are fully supported under linux, including working 7.1 channel LPCM audio over HDMI:

- GeForce 8200 & 8300, nForce 750a & 780a SLI mGPU for AMD
- GeForce 9300 & 9400 mGPU for Intel

Looking at the installation guide for the latest 180.37 release under the supported GPU section, we have these AMD chipsets as being supported by the current driver:

GeForce 8300 0x0848
GeForce 8200 0x0849
nForce 730a 0x084A
GeForce 8200 0x084B
nForce 780a SLI 0x084C
nForce 750a SLI 0x084D

But, does support here mean that they are fully supported, i.e. including 7.1 channel LPCM over HDMI audio?

On the Intel side, when one searches for 9300 and 9400 in that list, these entries come up:

GeForce 9400 GT 0x042C
GeForce 9300M G 0x042E
GeForce 9300 GE 0x06E0
GeForce 9300 GS 0x06E1
GeForce 9300M GS 0x06E5
GeForce 9300M GS 0x06E9
GeForce 9400M G 0x0862
GeForce 9400M 0x0863

none of which seem to be the 9300/9400 chipset IGPs. Does this mean that those IGPs are NOT supported by the current linux driver (and if so, is support planned in a (near term) future version of the linux driver?) Thanks in advance for help, tips and pointers.

[primerib]

Myself and at least 2 other people I know are looking for the same information as well. Thanks for posting, hopefully Stephen or someone can clear this up.

[pike2k]

HEAR HEAR!

*BUMP*

[dragilla]

Hi there,

I'm a proud owner of a NV 9300M GS. I'm trying to force it to play 7.1 pcm audio over hdmi for a week now or so. The problem seems to be alsa which (afaik) supports only up to 6 channels (?). So does mplayer in my experience. Maybe you can help me make it work and together we can answer the question: does it support 7.1 lpcm or not.
Awaiting your answer.

regards,
--
Luke

[scarycall]

I also tried in vain to get true multichannel pcm through HDMI. I have the 8200 and the SPDIF -> HDMI allows me to send AC3/DTS and stereo PCM through HDMI along with video.

But... since the intel chipset allows multichannel pcm and nvidia currently does not, I am led to believe it is a problem with the driver and not alsa's fault.

This last piece is the only thing holding me back from a true server based htpc. (long ago, my entire CD/DVD collection went into archival storage)

[scarycall]

Suprised noone has any information on this. Does everyone focus on the video and neglect the benefits of high definition audio?

[apaige]

The nvidia graphics driver has nothing to do with audio; ALSA does. Currently, ALSA's nvhdmi driver only supports stereo PCM.

static struct hda_pcm_stream nvhdmi_pcm_digital_playback = {
    .substreams = 1,
    .channels_min = 2,
    .channels_max = 2,
    .nid = 0x4, /* NID to query formats and rates and setup streams */
    .rates = SNDRV_PCM_RATE_48000,
    .maxbps = 16,
    .formats = SNDRV_PCM_FMTBIT_S16_LE,
    .ops = {
        .open = nvhdmi_dig_playback_pcm_open,
        .close = nvhdmi_dig_playback_pcm_close,
        .prepare = nvhdmi_dig_playback_pcm_prepare
    },
};

[philipl]

An official patch to add 7.1 support for some IGPs (probably all the ones where the hardware can do it) just showed up on LKML.

http://lkml.indiana.edu/hypermail/li...6.0/00081.html