drm/etnaviv: flush shader L1 cache after user commandstream

commit 4f8dbadef085ab447a01a8d4806a3f629fea05ed upstream.

The shader L1 cache is a writeback cache for shader loads/stores
and thus must be flushed before any BOs backing the shader buffers
are potentially freed.

Cc: stable@vger.kernel.org
Reviewed-by: Christian Gmeiner <cgmeiner@igalia.com>
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/gpu/drm/etnaviv/etnaviv_buffer.c

@@ -482,7 +482,8 @@ void etnaviv_buffer_queue(struct etnaviv_gpu *gpu, u32 exec_state,
 	} else {
 		CMD_LOAD_STATE(buffer, VIVS_GL_FLUSH_CACHE,
 				       VIVS_GL_FLUSH_CACHE_DEPTH |
-				       VIVS_GL_FLUSH_CACHE_COLOR);
+				       VIVS_GL_FLUSH_CACHE_COLOR |
+				       VIVS_GL_FLUSH_CACHE_SHADER_L1);
 		if (has_blt) {
 			CMD_LOAD_STATE(buffer, VIVS_BLT_ENABLE, 0x1);
 			CMD_LOAD_STATE(buffer, VIVS_BLT_SET_COMMAND, 0x1);