On Wed, 16 Mar 2016 08:48:58 +0100, Yang, Libin wrote: > > Hi Takashi, > > > -----Original Message----- > > From: Takashi Iwai [mailto:tiwai@xxxxxxx] > > Sent: Wednesday, March 16, 2016 3:35 PM > > To: libin.yang@xxxxxxxxxxxxxxx > > Cc: alsa-devel@xxxxxxxxxxxxxxxx; Yang, Libin; Lin, Mengdong > > Subject: Re: [PATCH] ALSA: hda - codec add DP MST support > > for connection list > > > > On Wed, 16 Mar 2016 02:47:31 +0100, > > libin.yang@xxxxxxxxxxxxxxx wrote: > > > > > > From: Libin Yang <libin.yang@xxxxxxxxxxxxxxx> > > > > > > This patches adds the support of connection list for DP MST. > > > With this, hdmi driver in DP MST mode can easily reuse > > > the connection list mechanism. > > > > > > Signed-off-by: Libin Yang <libin.yang@xxxxxxxxxxxxxxx> > > > > The merge window was already opened, so it's too late for this kind of > > change for 4.6, in anyway. > > That's OK. We can wait for later version. What do you think put this patch > and my later patches for MST in the topic branch, such as hdmi-jack brach > like before. Later patches for MST needs gfx driver support and our > gfx driver is not ready for it. > > > > > But, the fundamental question: why do we need to manage the cached > > list of the widget connection with a device index? In other words, if > > you have a different device index, does the widget connection itself > > also change? > > Based on my test, it should be the same. But from the spec, it says: > > 7.3.3.42 Device Select > For Digital Display Pin Widget that is multi stream capable, the Device Select control determines which > Device Entry is currently selected and accessible by the Pin Widget verbs which are controlling the sink > device operations. This control verb is only required if it is a Digital Display Pin Widget and multi stream > capable. > The index is in relation to the Device List associated with the widget. The index is a zero-based offset > into the Device List. Once the Device Entry is selected by the Set index, all subsequent Pin Widget verbs > controlling the sink device operations will be directed to the selected Device Entry, until the Device Select > verb get updated with a new value. These Pin Widget verbs include: > Connection Select > Get Connection List Entry > Amplifier Gain/Mute > Power State > Pin Widget Control > ELD Data > DIP-Size > DIP-Index > DIP-Data > DIP-XmitCtrl > Content Protection Control > ASP Channel Mapping > > So my understand is this may be changed. But the pin widget is the terminal. So, if you have a device index to choose a device there, the widget connection list itself doesn't change. Or am I missing anything? Takashi _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
