Romain Tisserand
Using KMS/DRM driver from WIP SDL2.0.6 on Linux/ARM SoC RockChip RK3328 (ARM Mali 450 MP2 GPU).
The current code is using GBM_BO_FORMAT_XRGB8888 as GBM buffer format specifier.
The Mali driver (it has been confirmed some other vendor implementations too) expects GBM_FORMAT_XRGB8888.
The Mesa implementation is actually handling both values as the same, but it's not implemented like this into every gbm.h vendor header.
https://github.com/ideak/mesa/blob/master/src/gbm/backends/dri/gbm_dri.c
So with stock SDL2 on my card (Mali vendor implementation), it does not work, eglCreateWindowSurface fails, and gbm_is_format_supported fails too (with the BO variant).
It runs fine with GBM_FORMAT_XRGB8888.
Here is a link of the gbm.h from Mali user-space driver :
https://github.com/rockchip-linux/libmali/blob/rockchip/include/gbm.h
Simon Hug
KMSDRM_VideoInit allocates and frees some connectors and encoders but doesn't set the pointer to NULL after freeing. The cleanup code at the end may free one of those garbage pointer should an error happen in the initialization.
Manuel
The attached patch adds support for KMS/DRM context graphics.
It builds with no problem on X86_64 GNU/Linux systems, provided the needed libraries are present, and on ARM GNU/Linux systems that have KMS/DRM support and a GLES2 implementation.
Tested on Raspberry Pi: KMS/DRM is what the Raspberry Pi will use as default in the near future, once the propietary DispmanX API by Broadcom is overtaken by open graphics stack, it's possible to boot current Raspbian system in KMS mode by adding "dtoverlay=vc4-kms-v3d" to config.txt on Raspbian's boot partition.
X86 systems use KMS right away in every current GNU/Linux system.
Simple build instructions:
$./autogen.sh
$./configure --enable-video-kmsdrm
$make