svga: Fix imported surface view creation

When deciding to create a view with or without an alpha channel we need to
look at the SVGA3D format and not the PIPE format.

This fixes the glx-tfp piglit test for dri3/xa.

Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Charmaine Lee <charmainel@vmware.com>

src/gallium/drivers/svga/svga_resource_texture.c

@@ -1488,3 +1488,25 @@ svga_texture_transfer_unmap_upload(struct svga_context *svga,
 
    pipe_resource_reference(&st->upload.buf, NULL);
 }
+
+/**
+ * Does the device format backing this surface have an
+ * alpha channel?
+ *
+ * \param texture[in]  The texture whose format we're querying
+ * \return TRUE if the format has an alpha channel, FALSE otherwise
+ *
+ * For locally created textures, the device (svga) format is typically
+ * identical to svga_format(texture->format), and we can use the gallium
+ * format tests to determine whether the device format has an alpha channel
+ * or not. However, for textures backed by imported svga surfaces that is
+ * not always true, and we have to look at the SVGA3D utilities.
+ */
+boolean
+svga_texture_device_format_has_alpha(struct pipe_resource *texture)
+{
+   enum svga3d_block_desc block_desc =
+      svga3dsurface_get_desc(svga_texture(texture)->key.format)->block_desc;
+
+   return !!(block_desc & SVGA3DBLOCKDESC_ALPHA);
+}

src/gallium/drivers/svga/svga_resource_texture.h

@@ -313,4 +313,7 @@ void
 svga_texture_transfer_unmap_upload(struct svga_context *svga,
                                    struct svga_transfer *st);
 
+boolean
+svga_texture_device_format_has_alpha(struct pipe_resource *texture);
+
 #endif /* SVGA_TEXTURE_H */

src/gallium/drivers/svga/svga_shader.c

@@ -215,7 +215,6 @@ svga_init_shader_key_common(const struct svga_context *svga,
          key->tex[i].swizzle_r = view->swizzle_r;
          key->tex[i].swizzle_g = view->swizzle_g;
          key->tex[i].swizzle_b = view->swizzle_b;
-         key->tex[i].swizzle_a = view->swizzle_a;
 
          /* If we have a non-alpha view into an svga3d surface with an
           * alpha channel, then explicitly set the alpha channel to 1
@@ -223,13 +222,11 @@ svga_init_shader_key_common(const struct svga_context *svga,
           * in the svga texture key, since the imported format is
           * stored here and it may differ from the gallium format.
           */
-         if (!util_format_has_alpha(view->format)) {
-            enum svga3d_block_desc block_desc =
-               svga3dsurface_get_desc(svga_texture(view->texture)->key.format)->
-               block_desc;
-
-            if (block_desc & SVGA3DBLOCKDESC_ALPHA)
-               key->tex[i].swizzle_a = PIPE_SWIZZLE_1;
+         if (!util_format_has_alpha(view->format) &&
+             svga_texture_device_format_has_alpha(view->texture)) {
+            key->tex[i].swizzle_a = PIPE_SWIZZLE_1;
+         } else {
+            key->tex[i].swizzle_a = view->swizzle_a;
          }
       }
    }

src/gallium/drivers/svga/svga_state_sampler.c

@@ -44,7 +44,7 @@
 #include "svga_shader.h"
 #include "svga_state.h"
 #include "svga_surface.h"
-
+#include "svga3d_surfacedefs.h"
 
 /** Get resource handle for a texture or buffer */
 static inline struct svga_winsys_surface *
@@ -141,11 +141,11 @@ svga_validate_pipe_sampler_view(struct svga_context *svga,
        * create a BGRA view (and vice versa).
        */
       if (viewFormat == PIPE_FORMAT_B8G8R8X8_UNORM &&
-          texture->format == PIPE_FORMAT_B8G8R8A8_UNORM) {
+          svga_texture_device_format_has_alpha(texture)) {
          viewFormat = PIPE_FORMAT_B8G8R8A8_UNORM;
       }
       else if (viewFormat == PIPE_FORMAT_B8G8R8A8_UNORM &&
-          texture->format == PIPE_FORMAT_B8G8R8X8_UNORM) {
+               !svga_texture_device_format_has_alpha(texture)) {
          viewFormat = PIPE_FORMAT_B8G8R8X8_UNORM;
       }