KMSDRM with SDL2 kernel 6.6 scarthgap

[Khaled-ELGHA]

Hello,

I was able to make the SDL2 library works with KMSDRM with kernel 5.15 Kirkston but with kernel 6.6 Scarthgap it doesn't work. I also configured the kmsdrm to work in the .bbappend file since I am using Yocto. I can see from the log.configure that the kmsdrm is on but the application which was working with 5.15 is still not able to run with 6.6. However, KMSCube is working means KMSDRM is working from the kernel point of view. The messages that I got when debug are below:

INFO: video driver in use is: (null)
INFO: video driver 0: wayland
INFO: video driver 1: KMSDRM
INFO: video driver 2: (null)
INFO: video driver 3: (null)
INFO: Failed to initialize SDL: No available video device

 

Even if I specify the driver to be kmdrm I see the following

INFO: video driver in use is: (null)
INFO: video driver 0: wayland
INFO: video driver 1: KMSDRM
INFO: video driver 2: (null)
INFO: video driver 3: (null)
INFO: Failed to initialize SDL: kmsdrm not available

 

I don't know why it is still unavailable?

from the "log.do_configure" of Yocto I can see this:

-- SDL_KMSDRM (Wanted: ON): ON
-- SDL_KMSDRM_SHARED (Wanted: ON): ON

in the build folder of "libsdl2" I can see also this in the "CMakeCache.txt" file:

//Use KMS DRM video driver
SDL_KMSDRM:BOOL=ON

//Dynamically load KMS DRM support
SDL_KMSDRM_SHARED:BOOL=ON

 

I edited the bbappend by adding those two lines to switch the offscreen off and to make sure that the KMSDRM is working

EXTRA_OECMAKE += " \
-DSDL_VIVANTE=OFF \
-DSDL_OPENGL=OFF \
-DSDL_KMSDRM=ON \
-DSDL_OFFSCREEN=OFF \
"

What else can I do? any suggestions?
Thanks in advance

[Erwan SZYMANSKI]

Hello @Khaled-ELGHA ,
As a quick test, could you please try the following thing in your libsdl2_%.bbappend:

# Force gles2 and kmsdrm config for libsdl2
PACKAGECONFIG ??= " \
 ${PACKAGECONFIG_GL} \
 ${@bb.utils.filter('DISTRO_FEATURES', 'alsa pipewire pulseaudio vulkan', d)} \
 ${@bb.utils.contains('DISTRO_FEATURES', 'wayland', 'wayland gles2', '', d)} \
 ${@bb.utils.contains("TUNE_FEATURES", "neon","arm-neon","",d)} \
 kmsdrm \
 gles2 \
"

Can you try to add manually here kmsdrm and gles2 ?

Kind regards,
Erwan.

[Khaled-ELGHA]

Thank you for your quick reply

I already edited the "libsdl2_2.30.1.bbappend" which located in "/home/drawengine/projects-scarthgap/layers/meta-st/meta-st-openstlinux/recipes-graphics/libsdl2" as a quick test:

Do I need to also add gles2? I will do it anyway and comeback to you, I just wanted to show you the whole bbappend file

Thanks a lot

 

FILESEXTRAPATHS:prepend := "${THISDIR}/files:"

SRC_URI += "file://0001-Correction-of-bad-dlopen-for-libEGL.patch"

PACKAGECONFIG_GL = ""

PACKAGECONFIG ??= " \
 ${PACKAGECONFIG_GL} \
 ${@bb.utils.filter('DISTRO_FEATURES', 'alsa pipewire pulseaudio vulkan', d)} \
 ${@bb.utils.contains('DISTRO_FEATURES', 'wayland', 'wayland gles2', '', d)} \
 ${@bb.utils.contains("TUNE_FEATURES", "neon","arm-neon","",d)} \
 kmsdrm \
"

EXTRA_OECMAKE += " \
 -DSDL_VIVANTE=OFF \
 -DSDL_OPENGL=OFF \
 -DSDL_KMSDRM=ON \
 -DSDL_OFFSCREEN=OFF \
"

PACKAGECONFIG:class-nativesdk = " \
 ${PACKAGECONFIG_GL} \
 ${@bb.utils.filter('DISTRO_FEATURES', 'x11', d)} \
 kmsdrm \
"

EXTRA_OECMAKE:class-nativesdk: += " \
 -DSDL_VIVANTE=OFF \
 -DSDL_OPENGL=OFF \
 -DSDL_KMSDRM=ON \
 -DSDL_OFFSCREEN=OFF \
"

 

 

[Erwan SZYMANSKI]

Hello @Khaled-ELGHA ,
In the past, I needed to make LVGL graphic framework run thanks to libSDL2 linked to our GPU, and for a reason I needed to put this gles2 to fully activate the different features.

Moreover, if you still face some trouble, do not hesitate to launch the graphic application with strace to check the different libraries access that could potentially fail.

Let me know the results of your different tests.

Kind regards,
Erwan.