bus: sunxi-rsb: Fix shutdown

Function sunxi_rsb_hw_exit() is sometimes called with pm runtime
disabled, so in such cases pm_runtime_resume() will fail with -EACCES.

Instead of doing whole dance of enabling pm runtime and thus clock just
to disable it again immediately, just check if disabling clock is
needed. That way calling pm_runtime_resume() is not needed at all.

Fixes: 4a0dbc1 ("bus: sunxi-rsb: Implement runtime power management")
Signed-off-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20211121083537.612473-1-jernej.skrabec@gmail.com

Author: jernejsk

drivers/bus/sunxi-rsb.c

@@ -687,11 +687,11 @@ static int sunxi_rsb_hw_init(struct sunxi_rsb *rsb)
 
 static void sunxi_rsb_hw_exit(struct sunxi_rsb *rsb)
 {
-	/* Keep the clock and PM reference counts consistent. */
-	if (pm_runtime_status_suspended(rsb->dev))
-		pm_runtime_resume(rsb->dev);
 	reset_control_assert(rsb->rstc);
-	clk_disable_unprepare(rsb->clk);
+
+	/* Keep the clock and PM reference counts consistent. */
+	if (!pm_runtime_status_suspended(rsb->dev))
+		clk_disable_unprepare(rsb->clk);
 }
 
 static int __maybe_unused sunxi_rsb_runtime_suspend(struct device *dev)