[Mesa-dev] [PATCH 18.0] i965: Disable ARB_get_program_binary for compat profiles

[Jordan Justen]

The QT framework has a bug in their shader program cache, which is
built on GL_ARB_get_program_binary.

In an effort to allow them to fix the bug we don't enable more than 1
binary format for compatibility profiles.

This is only being done on the 18.0 release branch.

Ref: https://bugreports.qt.io/browse/QTBUG-66420
Ref: https://bugs.freedesktop.org/show_bug.cgi?id=105065
Cc: "18.0" <mesa-stable at lists.freedesktop.org>
Cc: Mark Janes <mark.a.janes at intel.com>
Cc: Kenneth Graunke <kenneth at whitecape.org>
Cc: Scott D Phillips <scott.d.phillips at intel.com>
Signed-off-by: Jordan Justen <jordan.l.justen at intel.com>
---
 docs/relnotes/17.4.0.html               | 2 +-
 src/mesa/drivers/dri/i965/brw_context.c | 9 ++++++++-
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/docs/relnotes/17.4.0.html b/docs/relnotes/17.4.0.html
index 412c0fc455e..fecdfe77969 100644
--- a/docs/relnotes/17.4.0.html
+++ b/docs/relnotes/17.4.0.html
@@ -53,7 +53,7 @@ Note: some of the new features are only available with certain drivers.
 <li>GL_ARB_enhanced_layouts on r600/evergreen+</li>
 <li>GL_ARB_bindless_texture on nvc0/kepler</li>
 <li>OpenGL 4.3 on r600/evergreen with hw fp64 support</li>
-<li>Support 1 binary format for GL_ARB_get_program_binary on i965</li>
+<li>Support 1 binary format for GL_ARB_get_program_binary on i965 (except in GL compatibility profiles)</li>
 </ul>
 
 <h2>Bug fixes</h2>
diff --git a/src/mesa/drivers/dri/i965/brw_context.c b/src/mesa/drivers/dri/i965/brw_context.c
index e9358b7bc9c..58527d77263 100644
--- a/src/mesa/drivers/dri/i965/brw_context.c
+++ b/src/mesa/drivers/dri/i965/brw_context.c
@@ -704,7 +704,14 @@ brw_initialize_context_constants(struct brw_context *brw)
       ctx->Const.AllowMappedBuffersDuringExecution = true;
 
    /* GL_ARB_get_program_binary */
-   ctx->Const.NumProgramBinaryFormats = 1;
+   /* The QT framework has a bug in their shader program cache, which is built
+    * on GL_ARB_get_program_binary. In an effort to allow them to fix the bug
+    * we don't enable more than 1 binary format for compatibility profiles.
+    * This is only being done on the 18.0 release branch.
+    */
+   if (ctx->API != API_OPENGL_COMPAT) {
+      ctx->Const.NumProgramBinaryFormats = 1;
+   }
 }
 
 static void
-- 
2.16.1