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From:   Neil Armstrong <narmstrong@baylibre.com>
To:     balbi@kernel.org
Cc:     Neil Armstrong <narmstrong@baylibre.com>,
        linux-usb@vger.kernel.org, linux-amlogic@lists.infradead.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        Kevin Hilman <khilman@baylibre.com>
Subject: [PATCH] usb: dwc3: meson-g12a: fix suspend resume regulator unbalanced disables
Date:   Wed, 21 Aug 2019 15:35:18 +0200
Message-Id: <20190821133518.9671-1-narmstrong@baylibre.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

When going in suspend, in Device mode, then resuming back leads
to the following:

unbalanced disables for USB_PWR_EN
WARNING: CPU: 0 PID: 163 at ../drivers/regulator/core.c:2590 _regulator_disable+0x104/0x180
Hardware name: Amlogic Meson G12A U200 Development Board (DT)
[...]
pc : _regulator_disable+0x104/0x180
lr : _regulator_disable+0x104/0x180
[...]
Call trace:
 _regulator_disable+0x104/0x180
 regulator_disable+0x40/0x78
 dwc3_meson_g12a_otg_mode_set+0x84/0xb0
 dwc3_meson_g12a_irq_thread+0x58/0xb8
 irq_thread_fn+0x28/0x80
 irq_thread+0x118/0x1b8
 kthread+0xf4/0x120
 ret_from_fork+0x10/0x18

This disables the regulator if enabled on suspend, and the reverse on
resume.

Fixes: c99993376f72 ("usb: dwc3: Add Amlogic G12A DWC3 glue")
Reported-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
---
 drivers/usb/dwc3/dwc3-meson-g12a.c | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/dwc3/dwc3-meson-g12a.c b/drivers/usb/dwc3/dwc3-meson-g12a.c
index bca7e92a10e9..12dda04b004d 100644
--- a/drivers/usb/dwc3/dwc3-meson-g12a.c
+++ b/drivers/usb/dwc3/dwc3-meson-g12a.c
@@ -564,7 +564,13 @@ static int __maybe_unused dwc3_meson_g12a_runtime_resume(struct device *dev)
 static int __maybe_unused dwc3_meson_g12a_suspend(struct device *dev)
 {
 	struct dwc3_meson_g12a *priv = dev_get_drvdata(dev);
-	int i;
+	int i, ret;
+
+	if (priv->vbus && priv->otg_phy_mode == PHY_MODE_USB_HOST) {
+		ret = regulator_disable(priv->vbus);
+		if (ret)
+			return ret;
+	}
 
 	for (i = 0 ; i < PHY_COUNT ; ++i) {
 		phy_power_off(priv->phys[i]);
@@ -599,6 +605,12 @@ static int __maybe_unused dwc3_meson_g12a_resume(struct device *dev)
 			return ret;
 	}
 
+       if (priv->vbus && priv->otg_phy_mode == PHY_MODE_USB_HOST) {
+               ret = regulator_enable(priv->vbus);
+		if (ret)
+			return ret;
+	}
+
 	return 0;
 }
 
-- 
2.22.0