Hi, On Mon, 30 Dec 2019, Pavel Machek wrote: > > From: Kai Vehmanen <kai.vehmanen@xxxxxxxxxxxxxxx> > > > > [ Upstream commit 2a2edfbbfee47947dd05f5860c66c0e80ee5e09d ] > > > > To support the DP-MST multiple streams via single connector feature, > > the HDMI driver was extended with the concept of backup PCMs. See > > commit 9152085defb6 ("ALSA: hda - add DP MST audio support"). [...] > This variable is not ever set in this patch, nor is it set elsewhere > in 4.19-stable. This means this patch is not suitable for stable. ack on that. In upstream this flag is only used by SOF (sound/soc/sof) currently, but SOF is not part of 4.19, so there are no users for this flag. Sorry for not catching this sooner. Br, Kai