There's some really weird shit going on here. I'm going to start from the beginning, as best as memory serves:
I had problems with surround sound on my HTPC, primarily due to the limitations of S/PDIF. I decided to upgrade to a video card that supported audio over HDMI. I wanted fanless, so my options were very limited. I went with a NVidia GT730 card. This was several months ago. As it turned out, Debian stable (Stretch) did not support this card. I think it was both a kernel issue and an nvidia-driver issue. So I upgraded to Debian testing (Buster). Initially, I ran into an SDDM black screen problem, which I reported. I was able to type in my password (don't ask why I even tried this) and my KDE desktop would load normally. This is why I thought is was an SDDM problem. After some time, Debian testing updated the nvidia-driver, and lo and behold, I got an SDDM login and a subsequent functioning KDE desktop session, no problem. I was happy. I think the update nvidia-driver version was 384.??, but I'm not sure. All was good for awhile, but then another nvidia-driver upgrade created the same problem as before. SDDM black screen, but I was still able to login to a functioning KDE session. Another nvidia-driver update (390.77) resulted in an SDDM black screen but I was still able to login to a KDE session with a working desktop. However, a subsequent update to KDE resulted in an SDDM black screen that also resulted in a black screen KDE session. What I mean by that is that SDDM allowed me to login, but KDE then also presented a black screen. I could enter commands to reboot the system, so the KDE session was active but there was no display. My setup is this: HTPC connected to a Marantz AV7005 receiver via HDMI. Marantz receiver connected to a Samsung 4k TV via HDMI. The Marantz receiver is limited to 1920x1080 video input. The nvidia-driver correctly detects this. The first time I experienced this problem I applied a firmware update to my Marantz receiver, but the problem persisted. When I connect my HTPC directly to the TV there is no display problem at all, but there is no way to get surround sound working that way (ARC is non-functional and S/PDIF outputs digital stereo, not surround). I suspected some type of resolution "handshaking" issue, so I searched the Internet for tips on forcing resolution settings with NVidia drivers. I came across instances where people were using xorg.conf to override system defaults (as you suggested) so I created a file using the NVidia utility and placed it in /etc/X11/. To my surprise (according to Debian xorg.conf is deprecated) it worked. Unfortunately, the fix was temporary. I successfully logged in via SDDM and was presented with a functioning KDE desktop session several times. I was very happy. I subsequently installed Kodi and a few other applications that I use, but discovered sound was no longer working. I checked all the multimedia settings, pulse audio, Kodi audio settings, etc. etc. etc. and could still not get sound working. It was working briefly, which is why I went and installed Kodi in the first place. During the process of trying to resolve the sound issues, I rebooted, only to find I now have both a black SDDM screen AND a black KDE session. I'm right back where I started, several days and multiple installations (Kubuntu, Ubuntu, Stretch, Buster) later, including trying out experimental nvidia-driver. Fuck me. Shit works, and then it doesn't, for no apparent reason. On Wed, Aug 29, 2018, at 19:27, Vojtech Bocek wrote: > Yeah, xorg should be self-configuring now, but I think you can still use > xorg.conf file. Doing this should have the desired effect, I think, and > it's worth trying out (if it doesn't work, just remove xorg.conf): > > cp -i /etc/nvidia/nvidia-drm-outputclass.conf /etc/X11/xorg.conf > > On Sat, 25 Aug 2018 at 09:25, Michael Haag <haa...@fastmail.net> wrote: > > > Yes. I should have mentioned I was sending the bug report from another > > machine. > > > > Thanks for the response, but to my knowledge Xorg.conf has been > > deprecated. I know there is no such file on either of my PCs. > > > > > > On Fri, Aug 24, 2018, at 16:20, Vojtech Bocek wrote: > > > Hello, > > > I'm assuming the bug report in your message is from the PC where it is > > > working, since the Xorg.0.log contains only HD monitor. > > > Try adding contents of /etc/nvidia/nvidia-drm-outputclass.conf (installed > > > by xserver-xorg-video-nvidia) into your Xorg.conf. > > > For me, the issue was that libglx from xorg was loaded instead of the one > > > by Nvidia, and this fixed it. > > > > > > I think the xserver-xorg-video-nvidia is supposed to be adding those > > config > > > lines automatically, but it is not. > >
