Hi Takashi,
-----Original Message----- From: Takashi Iwai [mailto:tiwai@suse.de] Sent: Friday, October 16, 2015 2:38 PM To: Raymond Yau Cc: Yang, Libin; ALSA Development Mailing List; airlied@linux.ie; Lin, Mengdong; Girdwood, Liam R; tanuk@iki.fi; David Henningsson Subject: Re: [alsa-devel] DP1.2 MST audio support discussion
On Fri, 16 Oct 2015 02:32:50 +0200, Raymond Yau wrote:
Do it mean that only one DP MST port and no HDMI port on the
same
graphic
card ?
No.
If there is only one HDMI and one Display Port, this mean that there
are
two pin complexes
Yes, and the mapping doesn't change in this case as before.
How about the name of jack detection kctl of three Display Port
monitors
which are created on the same pin complex but different dev_index ?
It's one of the models we've considered. Basically the number of devices can be up to 64 (or such) per pin. For Intel case, due to the limitation of converters, it's up to 3. For other GPUs that may drive more simultaneous outputs, the number increases in square. If a GPU may handle 16 outputs, it'll be 256 entries.
Although the 256 entries are certainly manageable as kctl, whether this is the best representation for user-space is a question.
This is what I concern. Each device entry should have one tag for unsol event. This means each device entry will create a jack?
Will three three display port monitor playback devices always play different stream even when the displays are in clone mode ?
The clone mode is another messy part...
If DP MST are dasiy chained, the unplug of the first monitor from
Display
Port will cause all DP monitor in the dasiy chain disconnect
Yes.
Do the power off of the Display Port in the middle of the dasiy chain
also
affect the last display port mointor in the dasiy chain ?
Possibly. But it's not what we really care, as this is the thing the graphics side should handle.
Takashi