Mesa (master): i965/gen4-5: Cope with immutable-format texture revalidation

[Chris Forbes]

Module: Mesa
Branch: master
Commit: f68a973dfb8926ac872b0b0e3b4b5c2163389d06
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=f68a973dfb8926ac872b0b0e3b4b5c2163389d06

Author: Chris Forbes <chrisf at ijw.co.nz>
Date:   Mon Dec  8 20:37:00 2014 +1300

i965/gen4-5: Cope with immutable-format texture revalidation

This is unfortunately sometimes necessary due to rebasing levels when
rendering into them.

16 piglits crash -> pass, when building mesa with debug enabled.

Signed-off-by: Chris Forbes <chrisf at ijw.co.nz>
Reviewed-by: Kenneth Graunke <kenneth at whitecape.org>

---

 src/mesa/drivers/dri/i965/intel_tex_validate.c |   13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/intel_tex_validate.c b/src/mesa/drivers/dri/i965/intel_tex_validate.c
index 0bf0393..1d82768 100644
--- a/src/mesa/drivers/dri/i965/intel_tex_validate.c
+++ b/src/mesa/drivers/dri/i965/intel_tex_validate.c
@@ -98,10 +98,17 @@ intel_finalize_mipmap_tree(struct brw_context *brw, GLuint unit)
       return true;
    }
 
-   /* Immutable textures should not get this far -- they should have been
-    * created in a validated state, and nothing can invalidate them.
+   /* On recent generations, immutable textures should not get this far
+    * -- they should have been created in a validated state, and nothing
+    * can invalidate them.
+    *
+    * Unfortunately, this is not true on pre-Sandybridge hardware -- when
+    * rendering into an immutable-format depth texture we may have to rebase
+    * the rendered levels to meet alignment requirements.
+    *
+    * FINISHME: Avoid doing this.
     */
-   assert(!tObj->Immutable);
+   assert(!tObj->Immutable || brw->gen < 6);
 
    firstImage = intel_texture_image(tObj->Image[0][tObj->BaseLevel]);