drm: etnaviv: use previous GPU pipe state when pipe switching

Use the previous GPU pipe state when deciding which GPU caches should
be flushed prior to switching the current pipe.  This avoids infering
what the previously selected pipe was, and potentially flushing the
wrong caches.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>

drivers/gpu/drm/etnaviv/etnaviv_buffer.c

@@ -93,9 +93,10 @@ static inline void CMD_SEM(struct etnaviv_cmdbuf *buffer, u32 from, u32 to)
 		       VIVS_GL_SEMAPHORE_TOKEN_TO(to));
 }
 
-static void etnaviv_cmd_select_pipe(struct etnaviv_cmdbuf *buffer, u8 pipe)
+static void etnaviv_cmd_select_pipe(struct etnaviv_gpu *gpu,
+	struct etnaviv_cmdbuf *buffer, u8 pipe)
 {
-	u32 flush;
+	u32 flush = 0;
 
 	/*
 	 * This assumes that if we're switching to 2D, we're switching
@@ -103,10 +104,10 @@ static void etnaviv_cmd_select_pipe(struct etnaviv_cmdbuf *buffer, u8 pipe)
 	 * the 2D core, we need to flush the 3D depth and color caches,
 	 * otherwise we need to flush the 2D pixel engine cache.
 	 */
-	if (pipe == ETNA_PIPE_2D)
-		flush = VIVS_GL_FLUSH_CACHE_DEPTH | VIVS_GL_FLUSH_CACHE_COLOR;
-	else
+	if (gpu->exec_state == ETNA_PIPE_2D)
 		flush = VIVS_GL_FLUSH_CACHE_PE2D;
+	else if (gpu->exec_state == ETNA_PIPE_3D)
+		flush = VIVS_GL_FLUSH_CACHE_DEPTH | VIVS_GL_FLUSH_CACHE_COLOR;
 
 	CMD_LOAD_STATE(buffer, VIVS_GL_FLUSH_CACHE, flush);
 	CMD_SEM(buffer, SYNC_RECIPIENT_FE, SYNC_RECIPIENT_PE);
@@ -291,7 +292,7 @@ void etnaviv_buffer_queue(struct etnaviv_gpu *gpu, unsigned int event,
 		}
 
 		if (gpu->switch_context) {
-			etnaviv_cmd_select_pipe(buffer, cmdbuf->exec_state);
+			etnaviv_cmd_select_pipe(gpu, buffer, cmdbuf->exec_state);
 			gpu->exec_state = cmdbuf->exec_state;
 			gpu->switch_context = false;
 		}