From 9fe525e37b9a88e7f520f02c8c377d899145cf4e Mon Sep 17 00:00:00 2001
From: Nanley Chery <nanley.g.chery@intel.com>
Date: Wed, 24 Aug 2022 11:30:14 -0700
Subject: [PATCH] mesa/st: Set PIPE_MAP_DISCARD_RANGE in fallback_copy_image
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Enables some drivers to avoid reading from the destination when mapping it.

Acked-by: Marek Olšák <marek.olsak@amd.com>
Reviewed-by: Tapani Pälli <tapani.palli@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/18257>
---
 src/mesa/state_tracker/st_cb_copyimage.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/mesa/state_tracker/st_cb_copyimage.c b/src/mesa/state_tracker/st_cb_copyimage.c
index 633182dffd4..fefbff78999 100644
--- a/src/mesa/state_tracker/st_cb_copyimage.c
+++ b/src/mesa/state_tracker/st_cb_copyimage.c
@@ -615,10 +615,11 @@ fallback_copy_image(struct st_context *st,
          st_MapTextureImage(
                st->ctx, dst_image, dst_z,
                dst_x, dst_y, dst_w, dst_h,
-               GL_MAP_WRITE_BIT, &dst, &dst_stride);
+               GL_MAP_WRITE_BIT | GL_MAP_INVALIDATE_RANGE_BIT,
+               &dst, &dst_stride);
       } else {
          dst = pipe_texture_map(st->pipe, dst_res, 0, dst_z,
-                                 PIPE_MAP_WRITE,
+                                 PIPE_MAP_WRITE | PIPE_MAP_DISCARD_RANGE,
                                  dst_x, dst_y, dst_w, dst_h,
                                  &dst_transfer);
          dst_stride = dst_transfer->stride;