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From:   Marc Zyngier <maz@kernel.org>
To:     Neil Armstrong <narmstrong@baylibre.com>,
        Kevin Hilman <khilman@baylibre.com>
Cc:     Jerome Brunet <jbrunet@baylibre.com>,
        Martin Blumenstingl <martin.blumenstingl@googlemail.com>,
        Guillaume Tucker <guillaume.tucker@collabora.com>,
        kernel-team@android.com, dri-devel@lists.freedesktop.org,
        linux-amlogic@lists.infradead.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: [PATCH 1/2] drm/meson: dw-hdmi: Disable clocks on driver teardown
Date:   Fri, 20 Nov 2020 09:42:04 +0000
Message-Id: <20201120094205.525228-2-maz@kernel.org>
In-Reply-To: <20201120094205.525228-1-maz@kernel.org>
References: <20201120094205.525228-1-maz@kernel.org>
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The HDMI driver request clocks early, but never disable them, leaving
the clocks on even when the driver is removed.

Fix it by slightly refactoring the clock code, and register a devm
action that will eventually disable/unprepare the enabled clocks.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 drivers/gpu/drm/meson/meson_dw_hdmi.c | 43 ++++++++++++++++++---------
 1 file changed, 29 insertions(+), 14 deletions(-)

diff --git a/drivers/gpu/drm/meson/meson_dw_hdmi.c b/drivers/gpu/drm/meson/meson_dw_hdmi.c
index 7f8eea494147..29623b309cb1 100644
--- a/drivers/gpu/drm/meson/meson_dw_hdmi.c
+++ b/drivers/gpu/drm/meson/meson_dw_hdmi.c
@@ -145,8 +145,6 @@ struct meson_dw_hdmi {
 	struct reset_control *hdmitx_apb;
 	struct reset_control *hdmitx_ctrl;
 	struct reset_control *hdmitx_phy;
-	struct clk *hdmi_pclk;
-	struct clk *venci_clk;
 	struct regulator *hdmi_supply;
 	u32 irq_stat;
 	struct dw_hdmi *hdmi;
@@ -946,6 +944,29 @@ static void meson_disable_regulator(void *data)
 	regulator_disable(data);
 }
 
+static void meson_disable_clk(void *data)
+{
+	clk_disable_unprepare(data);
+}
+
+static int meson_enable_clk(struct device *dev, char *name)
+{
+	struct clk *clk;
+	int ret;
+
+	clk = devm_clk_get(dev, name);
+	if (IS_ERR(clk)) {
+		dev_err(dev, "Unable to get %s pclk\n", name);
+		return PTR_ERR(clk);
+	}
+
+	ret = clk_prepare_enable(clk);
+	if (!ret)
+		ret = devm_add_action_or_reset(dev, meson_disable_clk, clk);
+
+	return ret;
+}
+
 static int meson_dw_hdmi_bind(struct device *dev, struct device *master,
 				void *data)
 {
@@ -1026,19 +1047,13 @@ static int meson_dw_hdmi_bind(struct device *dev, struct device *master,
 	if (IS_ERR(meson_dw_hdmi->hdmitx))
 		return PTR_ERR(meson_dw_hdmi->hdmitx);
 
-	meson_dw_hdmi->hdmi_pclk = devm_clk_get(dev, "isfr");
-	if (IS_ERR(meson_dw_hdmi->hdmi_pclk)) {
-		dev_err(dev, "Unable to get HDMI pclk\n");
-		return PTR_ERR(meson_dw_hdmi->hdmi_pclk);
-	}
-	clk_prepare_enable(meson_dw_hdmi->hdmi_pclk);
+	ret = meson_enable_clk(dev, "isfr");
+	if (ret)
+		return ret;
 
-	meson_dw_hdmi->venci_clk = devm_clk_get(dev, "venci");
-	if (IS_ERR(meson_dw_hdmi->venci_clk)) {
-		dev_err(dev, "Unable to get venci clk\n");
-		return PTR_ERR(meson_dw_hdmi->venci_clk);
-	}
-	clk_prepare_enable(meson_dw_hdmi->venci_clk);
+	ret = meson_enable_clk(dev, "venci");
+	if (ret)
+		return ret;
 
 	dw_plat_data->regm = devm_regmap_init(dev, NULL, meson_dw_hdmi,
 					      &meson_dw_hdmi_regmap_config);
-- 
2.28.0