gallium: add PIPE_SHADER_CAP_MAX_UNROLL_ITERATIONS_HINT

This avoids a serious r600g bug leading to a GPU hang.
The chances this bug will get fixed are pretty low now.

I deeply regret listening to others and not pushing this patch, leaving
other users with a GPU-crashing driver. Yes, it should be fixed
in the compiler and it's ugly, but users couldn't care less about that.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=86720

Cc: 11.0 10.6 <[email protected]>
Reviewed-by: Brian Paul <[email protected]>

3 files changed, 8 insertions, 0 deletions

diff --git a/src/gallium/drivers/nouveau/nv30/nv30_screen.c b/src/gallium/drivers/nouveau/nv30/nv30_screen.c
index d4cf143b9a3..03301649e38 100644
--- a/src/gallium/drivers/nouveau/nv30/nv30_screen.c
+++ b/src/gallium/drivers/nouveau/nv30/nv30_screen.c
@@ -264,6 +264,8 @@ nv30_screen_get_shader_param(struct pipe_screen *pscreen, unsigned shader,
       case PIPE_SHADER_CAP_TGSI_FMA_SUPPORTED:
       case PIPE_SHADER_CAP_TGSI_ANY_INOUT_DECL_RANGE:
          return 0;
+      case PIPE_SHADER_CAP_MAX_UNROLL_ITERATIONS_HINT:
+         return 32;
       default:
          debug_printf("unknown vertex shader param %d\n", param);
          return 0;
@@ -305,6 +307,8 @@ nv30_screen_get_shader_param(struct pipe_screen *pscreen, unsigned shader,
       case PIPE_SHADER_CAP_TGSI_FMA_SUPPORTED:
       case PIPE_SHADER_CAP_TGSI_ANY_INOUT_DECL_RANGE:
          return 0;
+      case PIPE_SHADER_CAP_MAX_UNROLL_ITERATIONS_HINT:
+         return 32;
       default:
          debug_printf("unknown fragment shader param %d\n", param);
          return 0;
diff --git a/src/gallium/drivers/nouveau/nv50/nv50_screen.c b/src/gallium/drivers/nouveau/nv50/nv50_screen.c
index a4431f20e14..ec51d00f266 100644
--- a/src/gallium/drivers/nouveau/nv50/nv50_screen.c
+++ b/src/gallium/drivers/nouveau/nv50/nv50_screen.c
@@ -300,6 +300,8 @@ nv50_screen_get_shader_param(struct pipe_screen *pscreen, unsigned shader,
    case PIPE_SHADER_CAP_TGSI_FMA_SUPPORTED:
    case PIPE_SHADER_CAP_TGSI_ANY_INOUT_DECL_RANGE:
       return 0;
+   case PIPE_SHADER_CAP_MAX_UNROLL_ITERATIONS_HINT:
+      return 32;
    default:
       NOUVEAU_ERR("unknown PIPE_SHADER_CAP %d\n", param);
       return 0;
diff --git a/src/gallium/drivers/nouveau/nvc0/nvc0_screen.c b/src/gallium/drivers/nouveau/nvc0/nvc0_screen.c
index d34c8a2b07b..af8e5f72670 100644
--- a/src/gallium/drivers/nouveau/nvc0/nvc0_screen.c
+++ b/src/gallium/drivers/nouveau/nvc0/nvc0_screen.c
@@ -313,6 +313,8 @@ nvc0_screen_get_shader_param(struct pipe_screen *pscreen, unsigned shader,
       return 16; /* would be 32 in linked (OpenGL-style) mode */
    case PIPE_SHADER_CAP_MAX_SAMPLER_VIEWS:
       return 16; /* XXX not sure if more are really safe */
+   case PIPE_SHADER_CAP_MAX_UNROLL_ITERATIONS_HINT:
+      return 32;
    default:
       NOUVEAU_ERR("unknown PIPE_SHADER_CAP %d\n", param);
       return 0;