[Mesa-dev] [PATCH v2 5/9] panfrost: Bail out early when doing a wallpaper blit

[Boris Brezillon]

The wallpaper blit is a bit special in that the operation is targetting
the current FB, but the u_blitter logic creates a new surface for it
which makes util_framebuffer_state_equal() return false. In that case
we don't want a new FB descriptor to be emitted/attached, so let's just
copy the new state into ctx->pipe_framebuffer and exit the function.

Signed-off-by: Boris Brezillon <boris.brezillon at collabora.com>
Reviewed-by: Alyssa Rosenzweig <alyssa.rosenzweig at collabora.com>
---
Changes in v2:
* Add Alyssa's R-b
---
 src/gallium/drivers/panfrost/pan_context.c | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/src/gallium/drivers/panfrost/pan_context.c b/src/gallium/drivers/panfrost/pan_context.c
index 65e6824a9b03..a6412de76469 100644
--- a/src/gallium/drivers/panfrost/pan_context.c
+++ b/src/gallium/drivers/panfrost/pan_context.c
@@ -2369,10 +2369,22 @@ panfrost_set_framebuffer_state(struct pipe_context *pctx,
         if (util_framebuffer_state_equal(&ctx->pipe_framebuffer, fb))
                 return;
 
-        if (!ctx->wallpaper_batch && (!is_scanout || has_draws)) {
-                panfrost_flush(pctx, NULL, PIPE_FLUSH_END_OF_FRAME);
+        /* The wallpaper logic sets a new FB state before doing the blit and
+         * restore the old one when it's done. Those FB states are reported to
+         * be different because the surface they are pointing to are different,
+         * but those surfaces actually point to the same cbufs/zbufs. In that
+         * case we definitely don't want new FB descs to be emitted/attached
+         * since the job is expected to be flushed just after the blit is done,
+         * so let's just copy the new state and return here.
+         */
+        if (ctx->wallpaper_batch) {
+                util_copy_framebuffer_state(&ctx->pipe_framebuffer, fb);
+                return;
         }
 
+        if (!is_scanout || has_draws)
+                panfrost_flush(pctx, NULL, PIPE_FLUSH_END_OF_FRAME);
+
         /* Invalidate the FBO job cache since we've just been assigned a new
          * FB state.
          */
-- 
2.21.0