1 files changed, 44 insertions, 0 deletions
diff --git a/target/linux/bcm27xx/patches-5.4/950-0226-drm-vc4-Fix-synchronization-firmwarekms-against-GL-r.patch b/target/linux/bcm27xx/patches-5.4/950-0226-drm-vc4-Fix-synchronization-firmwarekms-against-GL-r.patch
new file mode 100644
index 0000000000..ccd6de065c
--- /dev/null
+++ b/target/linux/bcm27xx/patches-5.4/950-0226-drm-vc4-Fix-synchronization-firmwarekms-against-GL-r.patch
@@ -0,0 +1,44 @@
+From 87df00d6b301f5de54443ac7e3765dce983e8b6a Mon Sep 17 00:00:00 2001
+From: Eric Anholt <eric@anholt.net>
+Date: Thu, 28 Mar 2019 11:58:51 -0700
+Subject: [PATCH] drm/vc4: Fix synchronization firmwarekms against GL
+ rendering.
+
+We would present the framebuffer immediately without waiting for
+rendering to finish first, resulting in stuttering and flickering as a
+window was dragged around when the GPU was busy enough to not just win
+the race.
+
+Signed-off-by: Eric Anholt <eric@anholt.net>
+---
+ drivers/gpu/drm/vc4/vc4_firmware_kms.c | 5 +++--
+ 1 file changed, 3 insertions(+), 2 deletions(-)
+
+--- a/drivers/gpu/drm/vc4/vc4_firmware_kms.c
++++ b/drivers/gpu/drm/vc4/vc4_firmware_kms.c
+@@ -15,6 +15,7 @@
+  */
+ 
+ #include "drm/drm_atomic_helper.h"
++#include "drm/drm_gem_framebuffer_helper.h"
+ #include "drm/drm_plane_helper.h"
+ #include "drm/drm_crtc_helper.h"
+ #include "drm/drm_fourcc.h"
+@@ -291,7 +292,7 @@ static const struct drm_plane_funcs vc4_
+ };
+ 
+ static const struct drm_plane_helper_funcs vc4_primary_plane_helper_funcs = {
+-	.prepare_fb = NULL,
++	.prepare_fb = drm_gem_fb_prepare_fb,
+ 	.cleanup_fb = NULL,
+ 	.atomic_check = vc4_plane_atomic_check,
+ 	.atomic_update = vc4_primary_plane_atomic_update,
+@@ -299,7 +300,7 @@ static const struct drm_plane_helper_fun
+ };
+ 
+ static const struct drm_plane_helper_funcs vc4_cursor_plane_helper_funcs = {
+-	.prepare_fb = NULL,
++	.prepare_fb = drm_gem_fb_prepare_fb,
+ 	.cleanup_fb = NULL,
+ 	.atomic_check = vc4_plane_atomic_check,
+ 	.atomic_update = vc4_cursor_plane_atomic_update,