[Mesa-dev] [PATCH 3/3] i965, meta: Stop unlocking the texture to try and prevent deadlocks.

[Kristian Høgsberg]

From: Kenneth Graunke <kenneth at whitecape.org>

Unlocking the texture is not safe: another thread could come in and grab
it.  Now that we use a recursive mutex, this should work.  This also fixes
texture lock deadlocks in the new meta fast clear path.

Signed-off-by: Kenneth Graunke <kenneth at whitecape.org>
Reviewed-by: Kristian Høgsberg <krh at bitplanet.net>
Cc: Brian Paul <brianp at vmware.com>
---
 src/mesa/drivers/common/meta.c               | 18 ------------------
 src/mesa/drivers/dri/i965/brw_blorp_blit.cpp |  4 ----
 2 files changed, 22 deletions(-)

diff --git a/src/mesa/drivers/common/meta.c b/src/mesa/drivers/common/meta.c
index 4851286..90befd4 100644
--- a/src/mesa/drivers/common/meta.c
+++ b/src/mesa/drivers/common/meta.c
@@ -2773,7 +2773,6 @@ copytexsubimage_using_blit_framebuffer(struct gl_context *ctx, GLuint dims,
                                        GLint x, GLint y,
                                        GLsizei width, GLsizei height)
 {
-   struct gl_texture_object *texObj = texImage->TexObject;
    GLuint fbo;
    bool success = false;
    GLbitfield mask;
@@ -2782,8 +2781,6 @@ copytexsubimage_using_blit_framebuffer(struct gl_context *ctx, GLuint dims,
    if (!ctx->Extensions.ARB_framebuffer_object)
       return false;
 
-   _mesa_unlock_texture(ctx, texObj);
-
    _mesa_meta_begin(ctx, MESA_META_ALL & ~MESA_META_DRAW_BUFFERS);
 
    _mesa_GenFramebuffers(1, &fbo);
@@ -2834,7 +2831,6 @@ copytexsubimage_using_blit_framebuffer(struct gl_context *ctx, GLuint dims,
    success = mask == 0x0;
 
  out:
-   _mesa_lock_texture(ctx, texObj);
    _mesa_DeleteFramebuffers(1, &fbo);
    _mesa_meta_end(ctx);
    return success;
@@ -2852,7 +2848,6 @@ _mesa_meta_CopyTexSubImage(struct gl_context *ctx, GLuint dims,
                            GLint x, GLint y,
                            GLsizei width, GLsizei height)
 {
-   struct gl_texture_object *texObj = texImage->TexObject;
    GLenum format, type;
    GLint bpp;
    void *buf;
@@ -2897,8 +2892,6 @@ _mesa_meta_CopyTexSubImage(struct gl_context *ctx, GLuint dims,
       return;
    }
 
-   _mesa_unlock_texture(ctx, texObj); /* need to unlock first */
-
    /*
     * Read image from framebuffer (disable pixel transfer ops)
     */
@@ -2927,8 +2920,6 @@ _mesa_meta_CopyTexSubImage(struct gl_context *ctx, GLuint dims,
 
    _mesa_meta_end(ctx);
 
-   _mesa_lock_texture(ctx, texObj); /* re-lock */
-
    free(buf);
 }
 
@@ -3206,12 +3197,9 @@ _mesa_meta_GetTexImage(struct gl_context *ctx,
                        struct gl_texture_image *texImage)
 {
    if (_mesa_is_format_compressed(texImage->TexFormat)) {
-      struct gl_texture_object *texObj = texImage->TexObject;
       GLuint slice;
       bool result;
 
-      /* Need to unlock the texture here to prevent deadlock... */
-      _mesa_unlock_texture(ctx, texObj);
       for (slice = 0; slice < texImage->Depth; slice++) {
          void *dst;
          if (texImage->TexObject->Target == GL_TEXTURE_2D_ARRAY
@@ -3236,8 +3224,6 @@ _mesa_meta_GetTexImage(struct gl_context *ctx,
          if (!result)
             break;
       }
-      /* ... and relock it */
-      _mesa_lock_texture(ctx, texObj);
 
       if (result)
          return;
@@ -3539,15 +3525,11 @@ _mesa_meta_ClearTexSubImage(struct gl_context *ctx,
 {
    bool res;
 
-   _mesa_unlock_texture(ctx, texImage->TexObject);
-
    res = cleartexsubimage_using_fbo(ctx, texImage,
                                     xoffset, yoffset, zoffset,
                                     width, height, depth,
                                     clearValue);
 
-   _mesa_lock_texture(ctx, texImage->TexObject);
-
    if (res)
       return;
 
diff --git a/src/mesa/drivers/dri/i965/brw_blorp_blit.cpp b/src/mesa/drivers/dri/i965/brw_blorp_blit.cpp
index 1cf2d18..92c92aa 100644
--- a/src/mesa/drivers/dri/i965/brw_blorp_blit.cpp
+++ b/src/mesa/drivers/dri/i965/brw_blorp_blit.cpp
@@ -266,8 +266,6 @@ brw_blorp_copytexsubimage(struct brw_context *brw,
    int dst_slice = slice + dst_image->TexObject->MinLayer + dst_image->Face;
    int dst_level = dst_image->Level + dst_image->TexObject->MinLevel;
 
-   _mesa_unlock_texture(ctx, dst_image->TexObject);
-
    brw_blorp_blit_miptrees(brw,
                            src_mt, src_irb->mt_level, src_irb->mt_layer,
                            dst_mt, dst_level, dst_slice,
@@ -275,8 +273,6 @@ brw_blorp_copytexsubimage(struct brw_context *brw,
                            dstX0, dstY0, dstX1, dstY1,
                            GL_NEAREST, false, mirror_y);
 
-   _mesa_lock_texture(ctx, dst_image->TexObject);
-
    /* If we're copying to a packed depth stencil texture and the source
     * framebuffer has separate stencil, we need to also copy the stencil data
     * over.
-- 
2.0.0