[Mesa-dev] [PATCH] st/mesa: fix the layer of VDPAU surface samplers

[Nicolai Hähnle]

From: Nicolai Hähnle <nicolai.haehnle at amd.com>

A latent bug in VDPAU interop was exposed by commit
e5cc84dd43be066c1dd418e32f5ad258e31a150a.

Before that commit, the st_vdpau code created samplers with
first_layer == last_layer == 1 that the general texture handling code
would immediately delete and re-create, because the layer does not match
the information in the GL texture object.

This was correct behavior, because the imported resource because the
imported resource is supposed to have the correct offset already applied.

After that commit, the state tracker assumes that an existing sampler is
correct at all times.  Existing samplers are supposed to be deleted when
they may become invalid, and they will be created on-demand.  This meant
that the sampler with first_layer == last_layer == 1 stuck around, leading
to rendering artefacts (on radeonsi), command stream failures (on r600), and
assertions (in debug builds).

This patch fixes the problem by simply not creating a sampler at all in
st_vdpau_map_surface and relying on the generic texture code to do the right
thing.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=98512
Cc: 13.0 <mesa-stable at lists.freedesktop.org>
---
 src/mesa/state_tracker/st_vdpau.c | 12 ------------
 1 file changed, 12 deletions(-)

diff --git a/src/mesa/state_tracker/st_vdpau.c b/src/mesa/state_tracker/st_vdpau.c
index 7912057..770f0ff 100644
--- a/src/mesa/state_tracker/st_vdpau.c
+++ b/src/mesa/state_tracker/st_vdpau.c
@@ -182,21 +182,20 @@ static void
 st_vdpau_map_surface(struct gl_context *ctx, GLenum target, GLenum access,
                      GLboolean output, struct gl_texture_object *texObj,
                      struct gl_texture_image *texImage,
                      const void *vdpSurface, GLuint index)
 {
    struct st_context *st = st_context(ctx);
    struct st_texture_object *stObj = st_texture_object(texObj);
    struct st_texture_image *stImage = st_texture_image(texImage);
 
    struct pipe_resource *res;
-   struct pipe_sampler_view templ, **sampler_view;
    mesa_format texFormat;
 
    if (output) {
       res = st_vdpau_output_surface_dma_buf(ctx, vdpSurface);
 
       if (!res)
          res = st_vdpau_output_surface_gallium(ctx, vdpSurface);
 
    } else {
       res = st_vdpau_video_surface_dma_buf(ctx, vdpSurface, index);
@@ -226,31 +225,20 @@ st_vdpau_map_surface(struct gl_context *ctx, GLenum target, GLenum access,
    texFormat = st_pipe_format_to_mesa_format(res->format);
 
    _mesa_init_teximage_fields(ctx, texImage,
                               res->width0, res->height0, 1, 0, GL_RGBA,
                               texFormat);
 
    pipe_resource_reference(&stObj->pt, res);
    st_texture_release_all_sampler_views(st, stObj);
    pipe_resource_reference(&stImage->pt, res);
 
-   u_sampler_view_default_template(&templ, res, res->format);
-   templ.u.tex.first_layer = index & 1;
-   templ.u.tex.last_layer = index & 1;
-   templ.swizzle_r = GET_SWZ(stObj->base._Swizzle, 0);
-   templ.swizzle_g = GET_SWZ(stObj->base._Swizzle, 1);
-   templ.swizzle_b = GET_SWZ(stObj->base._Swizzle, 2);
-   templ.swizzle_a = GET_SWZ(stObj->base._Swizzle, 3);
-
-   sampler_view = st_texture_get_sampler_view(st, stObj);
-   *sampler_view = st->pipe->create_sampler_view(st->pipe, res, &templ);
-
    stObj->surface_format = res->format;
 
    _mesa_dirty_texobj(ctx, texObj);
    pipe_resource_reference(&res, NULL);
 }
 
 static void
 st_vdpau_unmap_surface(struct gl_context *ctx, GLenum target, GLenum access,
                        GLboolean output, struct gl_texture_object *texObj,
                        struct gl_texture_image *texImage,
-- 
2.7.4