[Buildroot] [PATCH 1/1] package/mesa3d: reorder platforms to fix EGL

[Joseph Kogut]

Mesa chooses the first platform specified in -Dplatforms as the default
EGL native platform. [0]

    Configure Options

    -D platforms=...
        List the platforms (window systems) to support. Its argument is
        a comma separated string such as -D platforms=x11,drm. It
        decides the platforms a driver may support. The first listed
        platform is also used by the main library to decide the native
        platform.

This has the effect of breaking EGL applications running on X11 and
possibly Wayland when the first platform specified isn't x11 or wayland,
and EGL_PLATFORM isn't set.

Reorder the specified platforms to use x11, wayland, and drm before
surfaceless, as this is the order chosen by other common distributions,
such as Arch Linux [1], Debian [2], and Fedora [3].

Users preferring drm or surfaceless over x11 or wayland likely know how
to override the native EGL platform, and likely have x11 and wayland
disabled anyway.

[0] https://www.mesa3d.org/egl.html
[1] https://git.archlinux.org/svntogit/packages.git/tree/trunk/PKGBUILD?h=packages/mesa#n45
[2] https://salsa.debian.org/xorg-team/lib/mesa/-/blob/fb8c1efb57ea8106525ed01c41218164f8be7f3b/debian/rules#L38
[3] https://src.fedoraproject.org/rpms/mesa/blob/master/f/mesa.spec#_337

Signed-off-by: Joseph Kogut <joseph.kogut at gmail.com>
---

This is a follow up to a previous email I sent the mailing list [0] about
broken EGL apps when using mesa3d with x11.

I discovered the cause of this issue is the ordering of platforms when
building mesa3d, making surfaceless the default native platform.

I suggested adding a config to specify the default native platform, but
after further review, I believe that simply reordering the enabled
platforms should be adequate.

[0] http://buildroot-busybox.2317881.n4.nabble.com/mesa3d-builds-with-ES2-report-no-ES2-enabled-EGL-configs-td255778.html

 package/mesa3d/mesa3d.mk | 34 +++++++++++++++++-----------------
 1 file changed, 17 insertions(+), 17 deletions(-)

diff --git a/package/mesa3d/mesa3d.mk b/package/mesa3d/mesa3d.mk
index 531dcf5b81..394428c053 100644
--- a/package/mesa3d/mesa3d.mk
+++ b/package/mesa3d/mesa3d.mk
@@ -167,7 +167,22 @@ endef
 MESA3D_POST_INSTALL_STAGING_HOOKS += MESA3D_REMOVE_OPENGL_HEADERS
 endif
 
-MESA3D_PLATFORMS = surfaceless
+ifeq ($(BR2_PACKAGE_MESA3D_NEEDS_X11),y)
+MESA3D_DEPENDENCIES += \
+	xlib_libX11 \
+	xlib_libXext \
+	xlib_libXdamage \
+	xlib_libXfixes \
+	xlib_libXrandr \
+	xlib_libXxf86vm \
+	xorgproto \
+	libxcb
+MESA3D_PLATFORMS += x11
+endif
+ifeq ($(BR2_PACKAGE_WAYLAND),y)
+MESA3D_DEPENDENCIES += wayland wayland-protocols
+MESA3D_PLATFORMS += wayland
+endif
 ifeq ($(BR2_PACKAGE_MESA3D_DRI_DRIVER),y)
 MESA3D_PLATFORMS += drm
 else ifeq ($(BR2_PACKAGE_MESA3D_GALLIUM_DRIVER_V3D),y)
@@ -189,22 +204,7 @@ MESA3D_PLATFORMS += drm
 else ifeq ($(BR2_PACKAGE_MESA3D_GALLIUM_DRIVER_RADEONSI),y)
 MESA3D_PLATFORMS += drm
 endif
-ifeq ($(BR2_PACKAGE_WAYLAND),y)
-MESA3D_DEPENDENCIES += wayland wayland-protocols
-MESA3D_PLATFORMS += wayland
-endif
-ifeq ($(BR2_PACKAGE_MESA3D_NEEDS_X11),y)
-MESA3D_DEPENDENCIES += \
-	xlib_libX11 \
-	xlib_libXext \
-	xlib_libXdamage \
-	xlib_libXfixes \
-	xlib_libXrandr \
-	xlib_libXxf86vm \
-	xorgproto \
-	libxcb
-MESA3D_PLATFORMS += x11
-endif
+MESA3D_PLATFORMS += surfaceless
 
 MESA3D_CONF_OPTS += \
 	-Dplatforms=$(subst $(space),$(comma),$(MESA3D_PLATFORMS))
-- 
2.26.2