linux-kernel - [PATCH 3/7] hwrng: omap3-rom - Call clk_disable

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Date:   Sat, 14 Sep 2019 14:02:56 -0700
From:   Tony Lindgren <tony@...mide.com>
To:     Matt Mackall <mpm@...enic.com>,
        Herbert Xu <herbert@...dor.apana.org.au>,
        linux-kernel@...r.kernel.org, linux-omap@...r.kernel.org
Cc:     linux-crypto@...r.kernel.org, Aaro Koskinen <aaro.koskinen@....fi>,
        Adam Ford <aford173@...il.com>,
        Pali Rohár <pali.rohar@...il.com>,
        Sebastian Reichel <sre@...nel.org>,
        Tero Kristo <t-kristo@...com>,
        Rob Herring <robh+dt@...nel.org>, devicetree@...r.kernel.org
Subject: [PATCH 3/7] 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 <aaro.koskinen@....fi>
Cc: Adam Ford <aford173@...il.com>
Cc: Pali Rohár <pali.rohar@...il.com>
Cc: Sebastian Reichel <sre@...nel.org>
Cc: Tero Kristo <t-kristo@...com>
Fixes: 1c6b7c2108bd ("hwrng: OMAP3 ROM Random Number Generator support")
Signed-off-by: Tony Lindgren <tony@...mide.com>
---
 drivers/char/hw_random/omap3-rom-rng.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/char/hw_random/omap3-rom-rng.c b/drivers/char/hw_random/omap3-rom-rng.c
--- a/drivers/char/hw_random/omap3-rom-rng.c
+++ b/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;
 }
 
-- 
2.23.0