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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Aaro Koskinen <aaro.koskinen@iki.fi>,
        Adam Ford <aford173@gmail.com>,
        =?UTF-8?q?Pali=20Roh=C3=A1r?= <pali.rohar@gmail.com>,
        Sebastian Reichel <sre@kernel.org>,
        Tero Kristo <t-kristo@ti.com>,
        Tony Lindgren <tony@atomide.com>,
        Herbert Xu <herbert@gondor.apana.org.au>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.14 041/161] hwrng: omap3-rom - Call clk_disable_unprepare() on exit only if not idled
Date:   Sun, 29 Dec 2019 18:18:09 +0100
Message-Id: <20191229162412.031459834@linuxfoundation.org>
In-Reply-To: <20191229162355.500086350@linuxfoundation.org>
References: <20191229162355.500086350@linuxfoundation.org>
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From: Tony Lindgren <tony@atomide.com>

[ Upstream commit eaecce12f5f0d2c35d278e41e1bc4522393861ab ]

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@iki.fi>
Cc: Adam Ford <aford173@gmail.com>
Cc: Pali Rohár <pali.rohar@gmail.com>
Cc: Sebastian Reichel <sre@kernel.org>
Cc: Tero Kristo <t-kristo@ti.com>
Fixes: 1c6b7c2108bd ("hwrng: OMAP3 ROM Random Number Generator support")
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 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
index 38b719017186..648e39ce6bd9 100644
--- a/drivers/char/hw_random/omap3-rom-rng.c
+++ b/drivers/char/hw_random/omap3-rom-rng.c
@@ -121,7 +121,8 @@ 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;
 }
 
-- 
2.20.1