radeonsi: make si_fence_server_signal flush pipe without work

glSignalSemaphoreEXT sometime doesn't signal the semaphore, it is
because radeonsi doesn't flush if gl context doesn't have pending
work. Fix the porblem by always submit ib.

Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Cc: 19.3 20.0 <mesa-stable@lists.freedesktop.org>
Tested-by: Marge Bot <https://gitlab.freedesktop.org/mesa/mesa/merge_requests/3779>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/merge_requests/3779>

diff --git a/src/gallium/drivers/radeonsi/si_fence.c b/src/gallium/drivers/radeonsi/si_fence.c
index e9dd3e937f25954500182843172c9992bcbcf3f0..26b5fc4bdba80654b4d5e2bd8c8f39ab6a881b7d 100644 (file)
--- a/src/gallium/drivers/radeonsi/si_fence.c
+++ b/src/gallium/drivers/radeonsi/si_fence.c
@@ -606,7 +606,11 @@ static void si_fence_server_signal(struct pipe_context *ctx,
         * Therefore, we must make sure that we flush the pipe to avoid
         * new work being emitted and getting executed before the signal
         * operation.
+        * 
+        * Set sctx->initial_gfx_cs_size to force IB submission even if
+        * it is empty.
         */
+       sctx->initial_gfx_cs_size = 0;
        si_flush_from_st(ctx, NULL, PIPE_FLUSH_ASYNC);
 }