From dabc7d8bf2d964460286168b52899c42b3369f8d Mon Sep 17 00:00:00 2001
From: Adam Jackson <ajax@redhat.com>
Date: Wed, 30 Oct 2019 11:20:40 -0400
Subject: [PATCH] xwayland: Fall back to GLES2 if we don't get at least GL 2.1
 in glamor

Some particularly unfortunate hardware (Intel gen3, mostly) will give
you GLES2 but not GL 2.1. Fall back to GLES2 for such cases so you still
get accelerated GLX.
---
 hw/xwayland/xwayland-glamor-gbm.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/hw/xwayland/xwayland-glamor-gbm.c b/hw/xwayland/xwayland-glamor-gbm.c
index e3d35ce10..2df12aeaa 100644
--- a/hw/xwayland/xwayland-glamor-gbm.c
+++ b/hw/xwayland/xwayland-glamor-gbm.c
@@ -948,6 +948,21 @@ xwl_glamor_gbm_init_egl(struct xwl_screen *xwl_screen)
             xwl_screen->egl_display, NULL, EGL_NO_CONTEXT, NULL);
     }
 
+    /* glamor needs either big-GL 2.1 or GLES2 */
+    if (xwl_screen->egl_context && epoxy_gl_version() < 21) {
+        const EGLint gles_attribs[] = {
+            EGL_CONTEXT_CLIENT_VERSION,
+            2,
+            EGL_NONE,
+        };
+
+        eglDestroyContext(xwl_screen->egl_display, xwl_screen->egl_context);
+        eglBindAPI(EGL_OPENGL_ES_API);
+        xwl_screen->egl_context = eglCreateContext(xwl_screen->egl_display,
+                                                   NULL, EGL_NO_CONTEXT,
+                                                   gles_attribs);
+    }
+
     if (xwl_screen->egl_context == EGL_NO_CONTEXT) {
         ErrorF("Failed to create EGL context\n");
         goto error;