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From:   Sasha Levin <sashal@kernel.org>
To:     linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc:     Amjad Ouled-Ameur <aouledameur@baylibre.com>,
        Jerome Brunet <jbrunet@baylibre.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Sasha Levin <sashal@kernel.org>, balbi@kernel.org,
        narmstrong@baylibre.com, khilman@baylibre.com,
        p.zabel@pengutronix.de, linux-usb@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org,
        linux-amlogic@lists.infradead.org
Subject: [PATCH AUTOSEL 5.16 029/217] usb: dwc3: meson-g12a: fix shared reset control use
Date:   Mon, 17 Jan 2022 21:16:32 -0500
Message-Id: <20220118021940.1942199-29-sashal@kernel.org>
In-Reply-To: <20220118021940.1942199-1-sashal@kernel.org>
References: <20220118021940.1942199-1-sashal@kernel.org>
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From: Amjad Ouled-Ameur <aouledameur@baylibre.com>

[ Upstream commit 4ce3b45704d5ef46fb4b28083c8aba6716fabf3b ]

reset_control_(de)assert() calls are called on a shared reset line when
reset_control_reset has been used. This is not allowed by the reset
framework.

Use reset_control_rearm() call in suspend() and remove() as a way to state
that the resource is no longer used, hence the shared reset line
may be triggered again by other devices. Use reset_control_rearm() also in
case probe fails after reset() has been called.

reset_control_rearm() keeps use of triggered_count sane in the reset
framework, use of reset_control_reset() on shared reset line should be
balanced with reset_control_rearm().

Signed-off-by: Amjad Ouled-Ameur <aouledameur@baylibre.com>
Reported-by: Jerome Brunet <jbrunet@baylibre.com>
Link: https://lore.kernel.org/r/20211112162827.128319-3-aouledameur@baylibre.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/usb/dwc3/dwc3-meson-g12a.c | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/drivers/usb/dwc3/dwc3-meson-g12a.c b/drivers/usb/dwc3/dwc3-meson-g12a.c
index d0f9b7c296b0d..bd814df3bf8b8 100644
--- a/drivers/usb/dwc3/dwc3-meson-g12a.c
+++ b/drivers/usb/dwc3/dwc3-meson-g12a.c
@@ -755,16 +755,16 @@ static int dwc3_meson_g12a_probe(struct platform_device *pdev)
 
 	ret = dwc3_meson_g12a_get_phys(priv);
 	if (ret)
-		goto err_disable_clks;
+		goto err_rearm;
 
 	ret = priv->drvdata->setup_regmaps(priv, base);
 	if (ret)
-		goto err_disable_clks;
+		goto err_rearm;
 
 	if (priv->vbus) {
 		ret = regulator_enable(priv->vbus);
 		if (ret)
-			goto err_disable_clks;
+			goto err_rearm;
 	}
 
 	/* Get dr_mode */
@@ -825,6 +825,9 @@ static int dwc3_meson_g12a_probe(struct platform_device *pdev)
 	if (priv->vbus)
 		regulator_disable(priv->vbus);
 
+err_rearm:
+	reset_control_rearm(priv->reset);
+
 err_disable_clks:
 	clk_bulk_disable_unprepare(priv->drvdata->num_clks,
 				   priv->drvdata->clks);
@@ -852,6 +855,8 @@ static int dwc3_meson_g12a_remove(struct platform_device *pdev)
 	pm_runtime_put_noidle(dev);
 	pm_runtime_set_suspended(dev);
 
+	reset_control_rearm(priv->reset);
+
 	clk_bulk_disable_unprepare(priv->drvdata->num_clks,
 				   priv->drvdata->clks);
 
@@ -892,7 +897,7 @@ static int __maybe_unused dwc3_meson_g12a_suspend(struct device *dev)
 		phy_exit(priv->phys[i]);
 	}
 
-	reset_control_assert(priv->reset);
+	reset_control_rearm(priv->reset);
 
 	return 0;
 }
@@ -902,7 +907,9 @@ static int __maybe_unused dwc3_meson_g12a_resume(struct device *dev)
 	struct dwc3_meson_g12a *priv = dev_get_drvdata(dev);
 	int i, ret;
 
-	reset_control_deassert(priv->reset);
+	ret = reset_control_reset(priv->reset);
+	if (ret)
+		return ret;
 
 	ret = priv->drvdata->usb_init(priv);
 	if (ret)
-- 
2.34.1