update -

i retired the 1600x1200 screen from 2007 (LP2065, which is the same panel as the 2007FP) and switched to my main 1080p monitor i use for the MiSTer - Acer Nitro XF243Y (https://www.rtings.com/monitor/reviews/acer/nitro-xf243y-pbmiiprx).

there wasnt anything wrong with the LP2065, but after doing a swap and test with my gaming monitor, it was apparent the monitor from 2007 doesnt hold up well in 2023. while very sharp and 4:3, the response time seemed sluggish compared to the Acer, almost like the LP2065 was on a slight video delay.

and the overall input lag experience was noticeable. the reported input lag of a LP2065 panel is ~16ms at 60hz

and the XF243Y is ~9ms at 60hz (see rtings review). while thats not too much of a difference in actual input lag, when combined with the almost instant response time of the XF243Y, the LP2065 just "feels" old.

also better colors on the Acer, and its an LED panel so it uses way less power and doesnt get hot. i am happy

@levitatingGuru Hey, I am wondering how you went about installing the kms driver? I am trying to also resolve the screen tearing but can't figure it our for the life of me. I have adapted the config.txt but I have read I have to install the KMS kernel 5.4 or something like that? is that correct?

Ok, the 5.15.? Kernel didn't work well. I had some screen dropouts again.
I then tried 5.10.60, which still had the screen tearing issue in Exult. After that I installed 5.10.64, which eliminates the screen tearing. So one of the commits between those versions fixed that. I will test this kernel further in the coming days and report back.

@Mrakobijes said in trying to use KMS driver yields no composite video output (Raspberry Pi 4):

dtoverlay-vc4-kms-v3d-pi4,composite=1

This looks like a mis-spelling, it should be just:

dtoverlay=vc4-kms-v3d,composite=1

and you should start with stock config.txt, instead of the one you're using, which has too many overclocking options which may conflict.

Note that this configuration is not fully supported by RetroPie yet and for the KMS driver is recommended to use an up-to-date Linux kernel/firmware.

You

I think long term, it's much better for Raspberry Pis to have a) an open source graphics stack, and b) a more 'standard' solution. as an educational tool it seems silly for the pi having bespoke APIs, and it meant that (as above) several pieces of software ended up being tied to that bespoke ecosystem out of convenience/necessity.

@sirhenrythe5th I wouldn't be in such a hurry.

I went back to looking into this again today. I've seen a bunch of threads around where people talk about vlc and using kms for hardware acceleration, so it seems like it is maybe supposed to work?

I captured the output from running it. The output looks identical regardless of whether I'm using FKMS or KMS. With FKMS, the image correctly shows on the screen (either hdmi0 or hdmi1, whatever I specify). With KMS, the output is the same, but the screen still just displays the terminal, nothing else shows up on either display.

Is there some other place I can look for errors, some other log file maybe?

Here's what the output is:

$ cvlc /home/pi/PieMarquee2/marquee/system/snes.png VLC media player 3.0.12 Vetinari (revision 3.0.12-1-0-gd147bb5e7e) [015a11d0] vlcpulse audio output error: PulseAudio server connection failure: Connection refused [015a2ac8] dbus interface error: Failed to connect to the D-Bus session daemon: Unable to autolaunch a dbus-daemon without a $DISPLAY for X11 [015a2ac8] main interface error: no suitable interface module [01528b58] main libvlc error: interface "dbus,none" initialization failed [015bc2a0] main interface error: no suitable interface module [01528b58] main libvlc error: interface "globalhotkeys,none" initialization failed [015bc2a0] dummy interface: using the dummy interface module... [aab014b0] gles2 generic error: parent window not available [aab00ca0] mmal_xsplitter vout display error: Failed to open Xsplitter:opengles2 module [aab014b0] xcb generic error: window not available [aab00ca0] mmal_xsplitter vout display error: Failed to open Xsplitter:xcb_x11 module

Well I finally found another image viewer that lets me specify something to display on the second hdmi port: vlc!

But although it worked fine on FKMS, nothing showed up when I ran it with KMS... not sure if I’m doing something wrong or if that is expected.

@phos
Did you get anywhere with this in the end?

@busywait Thanks for that, I added "composite=1" to the "dtoverlay" line in config.txt, and it has had some change, but the screen is still blank.

Now when I run modetest, the connector "composite-1" shows up, but its status is "unknown", and it has no associated encoder id.

The list of encoders has also changed to include TVDAC, but it has a crtc of 0.

TBH I'm not sure how connector, encoder, and crtc interrelate, and/or whether it's possible to fix the relations (assuming that's all the problem is).

@nemo93 Technically neither have I. It runs as a CD32 game if you rename the .CUE file. I've been running it like this for a while but 3.3 (or maybe an earlier version) seems to have broken it,

I'll wait to see what 3.4 brings.

it was too good to be true :( i was right it doesn't work https://github.com/libretro/RetroArch/pull/11590#issuecomment-743402918

i just updated system and is on 5.10.11

If anyone uses bgm with livewire setup it seem update removes the python-pygame which is needed. (tested on another base and was ok)
So you need to reinstall manually
or use the install script to remove and re install BGM and missing package

If you use @mitu tweak in cmdline.txt
snd-bcm2835.enable_compat_alsa=1
you can set audio so mixer can work to SYSDEFAULT or HW with PCM
if you dont use this and have new default setup
you use SYSDEFAULT or HW and HDMI

NOTE
If you touched the retropie config section audio settings, go back and set to reset to default

RetroPie updates have nothing to do with the audio - it's the OS updates (kernel/firmware) that can affect it. Of course, using an experimental/beta driver might not be the most stable configuration at this time, so you might encounter issues with it from kernel/firmware version to another.

Sorry the quality is so bad. Hopefully you can see the signal blanking out as I switch between the menu and the running system. The monitor's HDMI2 input notification appears in the top-right each time this happens.

The output resolution is 1080p@60 in both the system and the menu (I tried to show this but it's hard to see the monitor's OSD).

It feels more like the SDL window(?) is being recreated as I switch between the system and the menu.

With the FKMS driver, the monitor never blanks out and switching between the running system and the menu is instant.

@Clyde I just added some small changed the the RetroPie scriptmodule, the hard work was done upstream, by the AttractMode developer.

@mitu for more portage with opengl support (exagear and others)