iris: Use the linear version of the surface format during fast clears.

Newer gens (> 9) will start doing the linear -> sRGB conversion of the
clear color for us, if we use a sRGB surface format. So let's make sure
that doesn't happen and keep the same semantics as before.

Even though the hardware could convert the clear color for us during
fast clear, that converted color is only used for sampling. For resolve,
the original color would be used (without the conversion). So we convert
it ourselves and the same converted color gets used for both sampling
and resolving, simplifying the whole logic.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>

diff --git a/src/gallium/drivers/iris/iris_clear.c b/src/gallium/drivers/iris/iris_clear.c
index 9fc242526a403afdf33dd029169dd72569330b3e..6b0e665c3b315d44092f5234b873727a2b4a3421 100644 (file)
--- a/src/gallium/drivers/iris/iris_clear.c
+++ b/src/gallium/drivers/iris/iris_clear.c
@@ -269,7 +269,13 @@ fast_clear_color(struct iris_context *ice,
    iris_blorp_surf_for_resource(&ice->vtbl, &surf, p_res, res->aux.usage,
                                 level, true);
 
-   blorp_fast_clear(&blorp_batch, &surf, format,
+   /* In newer gens (> 9), the hardware will do a linear -> sRGB conversion of
+    * the clear color during the fast clear, if the surface format is of sRGB
+    * type. We use the linear version of the surface format here to prevent
+    * that from happening, since we already do our own linear -> sRGB
+    * conversion in convert_fast_clear_color().
+    */
+   blorp_fast_clear(&blorp_batch, &surf, isl_format_srgb_to_linear(format),
                     level, box->z, box->depth,
                     box->x, box->y, box->x + box->width,
                     box->y + box->height);