commit e13cbc3f1548dce17e46e0bd181d780f9f00853d
author Chris Dalton <csmartdalton@google.com> Tue Feb 04 21:58:19 2020 -0700
committer Skia Commit-Bot <skia-commit-bot@chromium.org> Wed Feb 05 17:12:37 2020 +0000
tree e5225b335dfab191469d681e2fdd6289763647dd
parent d2ccbb522eb062c777c7ab1d35f8596380814732

Don't use tessellation FB barrier after NVIDIA 440.00

This bug has already been fixed on newer drivers.

Bug: skia:9739
Change-Id: I8407d4198bc0610dd9a239969d1cf69942494c96
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/268639
Reviewed-by: Mark Kilgard US <mjk@nvidia.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Chris Dalton <csmartdalton@google.com>

src/gpu/gl/GrGLCaps.cpp

diff --git a/src/gpu/gl/GrGLCaps.cpp b/src/gpu/gl/GrGLCaps.cpp
index 71e3365..62f6378 100644
--- a/src/gpu/gl/GrGLCaps.cpp
+++ b/src/gpu/gl/GrGLCaps.cpp
@@ -3755,14 +3755,21 @@
         fDriverBlacklistMSAACCPR = true;
     }
 
-    if (shaderCaps->fTessellationSupport && kNVIDIA_GrGLDriver == ctxInfo.driver()) {
+    // http://skbug.com/9739
+    bool isNVIDIAPascal =
+            kNVIDIA_GrGLDriver == ctxInfo.driver() &&
+            ctxInfo.hasExtension("GL_NV_conservative_raster_pre_snap_triangles") &&  // Pascal+.
+            !ctxInfo.hasExtension("GL_NV_conservative_raster_underestimation");  // Volta+.
+    if (isNVIDIAPascal && ctxInfo.driverVersion() < GR_GL_DRIVER_VER(440, 00, 0)) {
         if (GR_IS_GR_GL(ctxInfo.standard())) {
+            // glMemoryBarrier wasn't around until version 4.2.
             if (ctxInfo.version() >= GR_GL_VER(4,2)) {
                 fRequiresManualFBBarrierAfterTessellatedStencilDraw = true;
             } else {
                 shaderCaps->fTessellationSupport = false;
             }
         } else {
+            // glMemoryBarrier wasn't around until es version 3.1.
             if (ctxInfo.version() >= GR_GL_VER(3,1)) {
                 fRequiresManualFBBarrierAfterTessellatedStencilDraw = true;
             } else {