Mesa (master): vc4: Detect and report kernel support for branching.

[Eric Anholt]

Module: Mesa
Branch: master
Commit: 83b8ca58e12ee13c4d5cd51c30c0fd19bf4f8bd2
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=83b8ca58e12ee13c4d5cd51c30c0fd19bf4f8bd2

Author: Eric Anholt <eric at anholt.net>
Date:   Thu Mar 10 15:18:31 2016 -0800

vc4: Detect and report kernel support for branching.

---

 src/gallium/drivers/vc4/vc4_screen.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/src/gallium/drivers/vc4/vc4_screen.c b/src/gallium/drivers/vc4/vc4_screen.c
index 5c17c55..f295ae0 100644
--- a/src/gallium/drivers/vc4/vc4_screen.c
+++ b/src/gallium/drivers/vc4/vc4_screen.c
@@ -32,6 +32,8 @@
 #include "util/u_format.h"
 #include "util/ralloc.h"
 
+#include <xf86drm.h>
+#include "vc4_drm.h"
 #include "vc4_screen.h"
 #include "vc4_context.h"
 #include "vc4_resource.h"
@@ -502,9 +504,17 @@ vc4_supports_branches(struct vc4_screen *screen)
 {
 #if USE_VC4_SIMULATOR
         return true;
-#else
-        return false;
 #endif
+
+        struct drm_vc4_get_param p = {
+                .param = DRM_VC4_PARAM_SUPPORTS_BRANCHES,
+        };
+        int ret = drmIoctl(screen->fd, DRM_IOCTL_VC4_GET_PARAM, &p);
+
+        if (ret != 0)
+                return false;
+
+        return p.value;
 }
 
 struct pipe_screen *