hwrng: omap3-rom - Call clk_disable_unprepare() on exit only if not idled

When unloading omap3-rom-rng, we'll get the following:

WARNING: CPU: 0 PID: 100 at drivers/clk/clk.c:948 clk_core_disable

This is because the clock may be already disabled by omap3_rom_rng_idle().
Let's fix the issue by checking for rng_idle on exit.

Cc: Aaro Koskinen <[email protected]>
Cc: Adam Ford <[email protected]>
Cc: Pali Rohár <[email protected]>
Cc: Sebastian Reichel <[email protected]>
Cc: Tero Kristo <[email protected]>
Fixes: 1c6b7c2 ("hwrng: OMAP3 ROM Random Number Generator support")
Signed-off-by: Tony Lindgren <[email protected]>
Signed-off-by: Herbert Xu <[email protected]>

Author: tmlind

drivers/char/hw_random/omap3-rom-rng.c

@@ -127,7 +127,8 @@ static int omap3_rom_rng_remove(struct platform_device *pdev)
 {
 	cancel_delayed_work_sync(&idle_work);
 	hwrng_unregister(&omap3_rom_rng_ops);
-	clk_disable_unprepare(rng_clk);
+	if (!rng_idle)
+		clk_disable_unprepare(rng_clk);
 	return 0;
 }