It seems to me, when it comes to config.txt, “less is better”. From reading various bugs reports and patches, changing settings in config.txt can have “unknown” effects.
pibootctl status --all | grep gpu.mem
│ gpu.mem │ │ 76 (Mb)
Without a gpu_mem setting in config.txt, this is the default setting the rpi firmware sets up. I don’t need that 12Mb difference, so I leave it alone, in keeping with my KISS principle approach to the config.txt. If I don’t need it, don’t set it. Who knows what else setting the gpu_mem changes… likely more than simply the difference in memory allocated. It could change some clock that then in turn effects kms in some way… who knows? The rpi kernel devs sometimes don’t even know.
I have tested youtube videos with both x11 and wayland with kms and the firefox browser, no playback issues for me. I believe my firefox installation uses the default configuration, no changes for wayland or hw accel.
All 3 kernels and the 2 raspberrypi-bootloader packages were upgraded today. I have built and pushed the new packages to the unstable branch when the mirrors sync.
You need to try and find out what is causing it for you. It won’t be long and 5.10 will go away. 5.15 is the next LTS and will be RPi’s default kernel.
My internet connection was terrible last night, all that I had time to test was the bootloaders, linux-rc and the rpi4-mainline+fkms… these worked fine.
As an example of how “picky” kms is… compare this config.txt with the one I posted above.
With this config.txt, while it boots fine, if I uncomment the vc4-kms-v3d, when plasma blanks the screen, it never returns. The screen stays black with just a mouse pointer. Why? I have no idea. I see nothing of note in the config to cause a difference in behavior… almost everything is commented out.
cat /boot/config.txt
# See /boot/overlays/README for all available options
# kernel
initramfs initramfs-linux.img followkernel
kernel=kernel8.img
# cpu/gpu
arm_64bit=1
#gpu_mem=64
# overclocking
arm_boost=1
#over_voltage=6
#arm_freq=2000
#core_freq=700
#gpu_freq=700
#v3d_freq=600
#isp_freq=700
#h264_freq=700
#core_freq_min=600
# gpio
#dtparam=i2c_arm=on
#dtparam=i2c1=on
# stop the blinking
dtparam=sd_poll_once
# sound
dtparam=audio=on
#hdmi_drive=2
# display
# 4K@30Hz
#hdmi_group=1
#hdmi_mode=95
# vc4
#dtoverlay=vc4-kms-v3d
#dtoverlay=vc4-fkms-v3d
disable_overscan=1
disable_splash=1
#max_framebuffers=2
hdmi_enable_4kp60=1
# 4K@60Hz
#hdmi_group=1
#hdmi_mode=97
# bluetooth
#dtoverlay=disable-bt
# wifi
#dtoverlay=disable-wifi
# argone one case
dtoverlay=argonone,hysteresis=5
dtparam=fantemp0=45,fanspeed0=10
dtparam=fantemp1=50,fanspeed1=50
dtparam=fantemp2=55,fanspeed2=100
So I continue to use software rendering on this particular rpi4.
You are not giving any info other than black screen and boot fail. I can only guess that that is all you see/get when it is first powered on. In that case I am assuming your monitor/tv is not getting detected. I have no idea what you are using for a monitor. I have no idea what you config.txt is. There has been 5 weeks of kernel upgrades since 5.10.83 which you keep falling back to.
With the very limited info you have given my guess would be for you to manually set up your monitor in config.txt like I have to do with my VIZIO tv or it will not boot.
When using xf86-video-fbdev the gpu memory uses gpu_mem= but with KMS the gpu uses CMA (gpu_mem= should be disabled when using CMA; it can cause issues). I do not know what the default gpu_mem is now but it used to be 64. While using a 4k monitor gpu_mem=512 should be ok for all use case’s with xf86-video-fbdev. I have see it run out of memory with a really stout satellite video stream.
don’t know, use kms, cma-512.
in case current system is mess, so build my own sway-21.12, everything clean & default, then update to 5.15.11 same result boot fail.
so, this time not my fault, right?
If x11, do you have a way to edit files on the SD card? I would suggest editing the config.txt and changing to dtoverlay=vc4-fkms-v3d and then try booting. If it boots, run sudo systemctl set-default multi-user. Then edit the config.txt and switch back to kms and reboot.
You should then see a login prompt. Login and run sudo systemctl start sddm
Then post the contents of /var/log/Xorg.0.log.