commit 49a7b1a5b8c228c3cf81fbe9d81b1150a14937b9
author Lars-Ivar Hesselberg Simonsen <lars-ivar.simonsen@arm.com> Mon Jun 02 13:44:56 2025 +0200
committer Marge Bot <marge-bot@fdo.invalid> Fri Jun 06 13:54:57 2025 +0000
tree 08f6bab2a569fc374cb018dc515388fd7607257f
parent 8953c13b15045598c1eadd54ff6c4d149f891a1b

panvk: Fix unsupported LogicOp NOOP blending

For formats that do not support LogicOps, NOOP should be treated as
COPY. This was implemented in nir/lower_blend, but an optimization in
PanVK would trigger for all NOOP that stopped this from happening.

This commit limits the NOOP optimization to supported formats.

Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/35367>

src/panfrost/vulkan/panvk_vX_blend.c

diff --git a/src/panfrost/vulkan/panvk_vX_blend.c b/src/panfrost/vulkan/panvk_vX_blend.c
index 28e9739..8d29abb 100644
--- a/src/panfrost/vulkan/panvk_vX_blend.c
+++ b/src/panfrost/vulkan/panvk_vX_blend.c
@@ -240,11 +240,9 @@
 {
    const struct pan_blend_rt_state *rt = &state->rts[rt_idx];
 
-   /* LogicOp requires a blend shader, unless it's a NOOP, in which case we just
-    * disable blending.
-    */
+   /* LogicOp requires a blend shader */
    if (state->logicop_enable)
-      return state->logicop_func != PIPE_LOGICOP_NOOP;
+      return true;
 
    /* alpha-to-one always requires a blend shader */
    if (state->alpha_to_one)
@@ -357,11 +355,6 @@
          continue;
       }
 
-      if (bs.logicop_enable && bs.logicop_func == PIPE_LOGICOP_NOOP) {
-         rt->equation.color_mask = 0;
-         continue;
-      }
-
       if (color_attachment_formats[i] == VK_FORMAT_UNDEFINED) {
          rt->equation.color_mask = 0;
          continue;
@@ -374,6 +367,14 @@
 
       rt->format = vk_format_to_pipe_format(color_attachment_formats[i]);
 
+      /* Disable blending for LOGICOP_NOOP unless the format is float/srgb */
+      if (bs.logicop_enable && bs.logicop_func == PIPE_LOGICOP_NOOP &&
+          !(util_format_is_float(rt->format) ||
+            util_format_is_srgb(rt->format))) {
+         rt->equation.color_mask = 0;
+         continue;
+      }
+
       rt->nr_samples = color_attachment_samples[i];
       rt->equation.blend_enable = cb->attachments[i].blend_enable;
       rt->equation.color_mask = cb->attachments[i].write_mask;