Just curious, is 5.10 with KMS on the horizon?

Beldar

Hello all!

I love what retropie has become and I appreciate all the work that has been put into it. So, thanks!

Unfortunately, I gave up on the raspberry pi 4 as a platform for retropie early on due to the screen tearing issue which ruined my enjoyment. However, I heard that the new kernel for raspian was on the horizon (with the real KMS driver support, I assume.) So, I'm curious if this means more stable video output is in the near future for retropie on the pi 4? I would love to dust off my pi 4 and use that.

Darksavior

@beldar The 5.10 kernel has been out. Just update your pi. The kms driver is not the default so you'll have to change it. Search the forum or the pi forum for more details. I haven't had any screen tearing but it does break daphne by giving me a black screen. No idea if it'll ever be fixed. The libretro emulators work fine.

Beldar

@darksavior
Thanks! Pardon my ignorance.

Ranma

@beldar
Yes it seems the screen tearing is a well-known issue on Pi 4 and 400. I had previously thought it was a Retroarch issue but the problems run across non-LR emus and games as well (also across other OS's - Recalbox and Batocera display this issue too). The move to the newer kernels seems to fix things in game, but sadly it breaks a few things too . I had issues with Kodi (HDMI kept flashing and blanking out, rendering it unusable), and my boot up video stopped working. If anyone knows of a short term solution to fix these using the newer kernel please let me know. If not, lets hope it does see a fix in the future. :-)

SaturnX

@ranma said in Just curious, is 5.10 with KMS on the horizon?:

@beldar
Yes it seems the screen tearing is a well-known issue on Pi 4 and 400. I had previously thought it was a Retroarch issue but the problems run across non-LR emus and games as well (also across other OS's - Recalbox and Batocera display this issue too). The move to the newer kernels seems to fix things in game, but sadly it breaks a few things too . I had issues with Kodi (HDMI kept flashing and blanking out, rendering it unusable), and my boot up video stopped working. If anyone knows of a short term solution to fix these using the newer kernel please let me know. If not, lets hope it does see a fix in the future. :-)

Unfortunately, the boot video/splashscreen has no short term fix as RetroPie uses dispmanx to display the boot video/splashscreen which doesn't work with the KMS driver. So until that's changed/updated you'll have to live with out.

I see it a small thing to give up to get rid of screen-tearing.

Ranma

@saturnx
Yes of course and I absolutely agree. I'm happy to wait it out.

Beldar

I actually just did a fresh installation of Retropie on a pi 4. I haven't switched to KMS and I just left everything as it is by default. For some reason I have virtually no screen tearing at all now even with fkms. I don't have an explanation for this. The only difference was the fresh install and a new micro SD card.

I still had the choppy frame rate in emulation station, but that was easily fixed buy turning up the minimum GPU frequency as has been discussed here already.

I'm overall very pleased with this set-up. I'm used to emulating on a 64 bit micro PC (a 7th generation Intel NUC.) Comparing the pi to the NUC, emulation for most of the systems I care about is virtually identical in performance. I'm sure it would matter if I cared about emulating N64 or polygonal arcade games, but it's pretty great.

With the pi 4 I've even been able to use a swapchain of 2, frame delay of 4, and 1 frame run ahead on Nestopia. I can get close to that with SNES9x for most games. Overall, I'm pleasantly surprised.

GreenHawk84

@beldar I don't notice tearing with SNES, NES, Genesis, Neo Geo, or Playstation. But I do notice it on Mortal Kombat 2 arcade which does run at a funky refresh rate. I also noticed it very badly with lr-flycast. Soul Calibur, MKGold, and NFL Blitz all had really bad tearing.