[Mesa-dev] [PATCH] llvmpipe: hack-fix bugs due to bogus bind flags

sroland at vmware.com sroland at vmware.com
Mon Jun 13 15:50:27 UTC 2016


From: Roland Scheidegger <sroland at vmware.com>

The gallium contract would be that bind flags must indicate all possible
bindings a resource might get used, but fact is the mesa state tracker does
not set bind flags correctly, and this is more or less unfixable due to GL.

This caused a bug with piglit arb_uniform_buffer_object-rendering-dsa
since 6e6fd911da8a1d9cd62fe0a8a4cc0fb7bdccfe02 - the commit is correct,
but it caused us to miss updates to fs UBOs completely, since the
corresponding buffer didn't have the appropriate bind flag set (thus we
wouldn't check if it is indeed currently bound).
See the discussion about this starting here:
https://lists.freedesktop.org/archives/mesa-dev/2016-June/119829.html

So, update the bind flags when we detect such usage.
Note we update this value for now only in places which matter for us - that
is creating sampler/surface view, or binding constant buffer. There's plenty
more places (setting streamout buffers, vertex/index buffers, ...) where
things can be set with the wrong bind flags, but the bind flags there never
matter.

While here also make sure we only set dirty constant bit when it's a fs
constant buffer - totally doesn't matter if it's vs/gs.
---
 src/gallium/drivers/llvmpipe/lp_state.h         |  2 +-
 src/gallium/drivers/llvmpipe/lp_state_derived.c |  2 +-
 src/gallium/drivers/llvmpipe/lp_state_fs.c      | 12 ++++++++++--
 src/gallium/drivers/llvmpipe/lp_state_sampler.c |  8 +++++---
 src/gallium/drivers/llvmpipe/lp_surface.c       |  9 ++++++++-
 src/gallium/drivers/llvmpipe/lp_texture.c       | 12 +++---------
 6 files changed, 28 insertions(+), 17 deletions(-)

diff --git a/src/gallium/drivers/llvmpipe/lp_state.h b/src/gallium/drivers/llvmpipe/lp_state.h
index 78918cf..f15d70d 100644
--- a/src/gallium/drivers/llvmpipe/lp_state.h
+++ b/src/gallium/drivers/llvmpipe/lp_state.h
@@ -46,7 +46,7 @@
 #define LP_NEW_STIPPLE       0x40
 #define LP_NEW_FRAMEBUFFER   0x80
 #define LP_NEW_DEPTH_STENCIL_ALPHA 0x100
-#define LP_NEW_CONSTANTS     0x200
+#define LP_NEW_FS_CONSTANTS  0x200
 #define LP_NEW_SAMPLER       0x400
 #define LP_NEW_SAMPLER_VIEW  0x800
 #define LP_NEW_VERTEX        0x1000
diff --git a/src/gallium/drivers/llvmpipe/lp_state_derived.c b/src/gallium/drivers/llvmpipe/lp_state_derived.c
index 9e29902..f76de6b 100644
--- a/src/gallium/drivers/llvmpipe/lp_state_derived.c
+++ b/src/gallium/drivers/llvmpipe/lp_state_derived.c
@@ -235,7 +235,7 @@ void llvmpipe_update_derived( struct llvmpipe_context *llvmpipe )
                                       llvmpipe->stencil_ref.ref_value);
    }
 
-   if (llvmpipe->dirty & LP_NEW_CONSTANTS)
+   if (llvmpipe->dirty & LP_NEW_FS_CONSTANTS)
       lp_setup_set_fs_constants(llvmpipe->setup,
                                 ARRAY_SIZE(llvmpipe->constants[PIPE_SHADER_FRAGMENT]),
                                 llvmpipe->constants[PIPE_SHADER_FRAGMENT]);
diff --git a/src/gallium/drivers/llvmpipe/lp_state_fs.c b/src/gallium/drivers/llvmpipe/lp_state_fs.c
index 7dceff7..3a678e3 100644
--- a/src/gallium/drivers/llvmpipe/lp_state_fs.c
+++ b/src/gallium/drivers/llvmpipe/lp_state_fs.c
@@ -2847,6 +2847,13 @@ llvmpipe_set_constant_buffer(struct pipe_context *pipe,
    /* note: reference counting */
    util_copy_constant_buffer(&llvmpipe->constants[shader][index], cb);
 
+   if (constants) {
+       if (!(constants->bind & PIPE_BIND_CONSTANT_BUFFER)) {
+         debug_printf("Illegal set constant without bind flag\n");
+         constants->bind |= PIPE_BIND_CONSTANT_BUFFER;
+      }
+   }
+
    if (shader == PIPE_SHADER_VERTEX ||
        shader == PIPE_SHADER_GEOMETRY) {
       /* Pass the constants to the 'draw' module */
@@ -2869,8 +2876,9 @@ llvmpipe_set_constant_buffer(struct pipe_context *pipe,
       draw_set_mapped_constant_buffer(llvmpipe->draw, shader,
                                       index, data, size);
    }
-
-   llvmpipe->dirty |= LP_NEW_CONSTANTS;
+   else {
+      llvmpipe->dirty |= LP_NEW_FS_CONSTANTS;
+   }
 
    if (cb && cb->user_buffer) {
       pipe_resource_reference(&constants, NULL);
diff --git a/src/gallium/drivers/llvmpipe/lp_state_sampler.c b/src/gallium/drivers/llvmpipe/lp_state_sampler.c
index 81b998a..4441f2a 100644
--- a/src/gallium/drivers/llvmpipe/lp_state_sampler.c
+++ b/src/gallium/drivers/llvmpipe/lp_state_sampler.c
@@ -169,11 +169,13 @@ llvmpipe_create_sampler_view(struct pipe_context *pipe,
 {
    struct pipe_sampler_view *view = CALLOC_STRUCT(pipe_sampler_view);
    /*
-    * XXX we REALLY want to see the correct bind flag here but the OpenGL
-    * state tracker can't guarantee that at least for texture buffer objects.
+    * XXX: bind flags from OpenGL state tracker are notoriously unreliable.
+    * This looks unfixable, so fix the bind flags instead when it happens.
     */
-   if (!(texture->bind & PIPE_BIND_SAMPLER_VIEW))
+   if (!(texture->bind & PIPE_BIND_SAMPLER_VIEW)) {
       debug_printf("Illegal sampler view creation without bind flag\n");
+      texture->bind |= PIPE_BIND_SAMPLER_VIEW;
+   }
 
    if (view) {
       *view = *templ;
diff --git a/src/gallium/drivers/llvmpipe/lp_surface.c b/src/gallium/drivers/llvmpipe/lp_surface.c
index 96f8ed8..dd1c446 100644
--- a/src/gallium/drivers/llvmpipe/lp_surface.c
+++ b/src/gallium/drivers/llvmpipe/lp_surface.c
@@ -131,8 +131,15 @@ llvmpipe_create_surface(struct pipe_context *pipe,
 {
    struct pipe_surface *ps;
 
-   if (!(pt->bind & (PIPE_BIND_DEPTH_STENCIL | PIPE_BIND_RENDER_TARGET)))
+   if (!(pt->bind & (PIPE_BIND_DEPTH_STENCIL | PIPE_BIND_RENDER_TARGET))) {
       debug_printf("Illegal surface creation without bind flag\n");
+      if (util_format_is_depth_or_stencil(surf_tmpl->format)) {
+         pt->bind |= PIPE_BIND_DEPTH_STENCIL;
+      }
+      else {
+         pt->bind |= PIPE_BIND_RENDER_TARGET;
+      }
+   }
 
    ps = CALLOC_STRUCT(pipe_surface);
    if (ps) {
diff --git a/src/gallium/drivers/llvmpipe/lp_texture.c b/src/gallium/drivers/llvmpipe/lp_texture.c
index ee41948..36f1c6b 100644
--- a/src/gallium/drivers/llvmpipe/lp_texture.c
+++ b/src/gallium/drivers/llvmpipe/lp_texture.c
@@ -542,14 +542,14 @@ llvmpipe_transfer_map( struct pipe_context *pipe,
       }
    }
 
-   /* Check if we're mapping the current constant buffer */
+   /* Check if we're mapping a current constant buffer */
    if ((usage & PIPE_TRANSFER_WRITE) &&
        (resource->bind & PIPE_BIND_CONSTANT_BUFFER)) {
       unsigned i;
       for (i = 0; i < ARRAY_SIZE(llvmpipe->constants[PIPE_SHADER_FRAGMENT]); ++i) {
          if (resource == llvmpipe->constants[PIPE_SHADER_FRAGMENT][i].buffer) {
             /* constants may have changed */
-            llvmpipe->dirty |= LP_NEW_CONSTANTS;
+            llvmpipe->dirty |= LP_NEW_FS_CONSTANTS;
             break;
          }
       }
@@ -640,13 +640,6 @@ llvmpipe_is_resource_referenced( struct pipe_context *pipe,
                                  unsigned level)
 {
    struct llvmpipe_context *llvmpipe = llvmpipe_context( pipe );
-
-   /*
-    * XXX checking only resources with the right bind flags
-    * is unsafe since with opengl state tracker we can end up
-    * with resources bound to places they weren't supposed to be
-    * (buffers bound as sampler views is one possibility here).
-    */
    if (!(presource->bind & (PIPE_BIND_DEPTH_STENCIL |
                             PIPE_BIND_RENDER_TARGET |
                             PIPE_BIND_SAMPLER_VIEW)))
@@ -687,6 +680,7 @@ llvmpipe_get_format_alignment( enum pipe_format format )
 
 /**
  * Create buffer which wraps user-space data.
+ * XXX unreachable.
  */
 struct pipe_resource *
 llvmpipe_user_buffer_create(struct pipe_screen *screen,
-- 
2.1.4



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