[Mesa-dev] [PATCH 05/17] gallium: reserve one shader buffer for shared storage

[Samuel Pitoiset]

At least, one shader buffer must be available for compute shaders.

Signed-off-by: Samuel Pitoiset <samuel.pitoiset at gmail.com>
---
 src/gallium/include/pipe/p_state.h     | 2 +-
 src/mesa/state_tracker/st_extensions.c | 6 ++++--
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/src/gallium/include/pipe/p_state.h b/src/gallium/include/pipe/p_state.h
index 2e4d283..051856e 100644
--- a/src/gallium/include/pipe/p_state.h
+++ b/src/gallium/include/pipe/p_state.h
@@ -61,7 +61,7 @@ extern "C" {
 #define PIPE_MAX_SHADER_INPUTS    80 /* 32 GENERIC + 32 PATCH + 16 others */
 #define PIPE_MAX_SHADER_OUTPUTS   80 /* 32 GENERIC + 32 PATCH + 16 others */
 #define PIPE_MAX_SHADER_SAMPLER_VIEWS 32
-#define PIPE_MAX_SHADER_BUFFERS   32
+#define PIPE_MAX_SHADER_BUFFERS   33
 #define PIPE_MAX_SHADER_IMAGES    32
 #define PIPE_MAX_TEXTURE_LEVELS   16
 #define PIPE_MAX_SO_BUFFERS        4
diff --git a/src/mesa/state_tracker/st_extensions.c b/src/mesa/state_tracker/st_extensions.c
index d066784..c198892 100644
--- a/src/mesa/state_tracker/st_extensions.c
+++ b/src/mesa/state_tracker/st_extensions.c
@@ -219,8 +219,10 @@ void st_init_limits(struct pipe_screen *screen,
                                           pc->MaxUniformBlocks);
 
       pc->MaxAtomicCounters = MAX_ATOMIC_COUNTERS;
-      pc->MaxAtomicBuffers = screen->get_shader_param(
-            screen, sh, PIPE_SHADER_CAP_MAX_SHADER_BUFFERS) / 2;
+      pc->MaxAtomicBuffers =
+         _clamp(screen->get_shader_param(screen, sh,
+                                         PIPE_SHADER_CAP_MAX_SHADER_BUFFERS),
+                0, PIPE_MAX_SHADER_BUFFERS - 1) / 2;
       pc->MaxShaderStorageBlocks = pc->MaxAtomicBuffers;
 
       /* Gallium doesn't really care about local vs. env parameters so use the
-- 
2.6.4