Created attachment 130616 [details] kernel 4.10.7 drm.debug=14 log Lenovo Thinkpad T440s connected via DisplayPort to a Dell U3415W will show all Audio Outputs as unplugged when Monitor is using DP 1.2 mode. When switching DP 1.2 (and thus MST) off Audio will work. This monitor is the primary and no secondary MST slave is connected. The attached log contains a bootup with Monitor attached in DP 1.2 mode, switch mode, restart X. Kernel 4.10.7.
I'm not sure 4.10 had MST audio support fully implemented. Please test with a more recent kernel. If 4.11 doesn't work, then please test the very latest development tree 'git://anongit.freedesktop.org/drm-tip drm-tip'
I tested Kernel 4.11-rc4 yesterday and indeed it works with it. As soon as kernel 4.11 gets released I'd report back and if it still works this could be closed. Thx.
(In reply to Daniel Exner from comment #2) > I tested Kernel 4.11-rc4 yesterday and indeed it works with it. > > As soon as kernel 4.11 gets released I'd report back and if it still works > this could be closed. Thx. Hello Daniel, It seems that the problem is fixed. I'll change the status to closed, if there is any new information about this case, please share it and change the tag to REOPEN. Thank you.
Use of freedesktop.org services, including Bugzilla, is subject to our Code of Conduct. How we collect and use information is described in our Privacy Policy.