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From:   Guenter Roeck <linux@roeck-us.net>
To:     Peter Chen <peter.chen@freescale.com>
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
        Guenter Roeck <linux@roeck-us.net>,
        Michael Grzeschik <m.grzeschik@pengutronix.de>,
        stable@vger.kernel.org
Subject: [PATCH] usb: chipidea: host: Disable port power only if previously enabled
Date:   Thu, 26 Dec 2019 07:57:54 -0800
Message-Id: <20191226155754.25451-1-linux@roeck-us.net>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On shutdown, ehci_power_off() is called unconditionally to power off
each port, even if it was never called to power on the port.
For chipidea, this results in a call to ehci_ci_portpower() with a request
to power off ports even if the port was never powered on.
This results in the following warning from the regulator code.

WARNING: CPU: 0 PID: 182 at drivers/regulator/core.c:2596 _regulator_disable+0x1a8/0x210
unbalanced disables for usb_otg2_vbus
Modules linked in:
CPU: 0 PID: 182 Comm: init Not tainted 5.4.6 #1
Hardware name: Freescale i.MX7 Dual (Device Tree)
[<c0313658>] (unwind_backtrace) from [<c030d698>] (show_stack+0x10/0x14)
[<c030d698>] (show_stack) from [<c1133afc>] (dump_stack+0xe0/0x10c)
[<c1133afc>] (dump_stack) from [<c0349098>] (__warn+0xf4/0x10c)
[<c0349098>] (__warn) from [<c0349128>] (warn_slowpath_fmt+0x78/0xbc)
[<c0349128>] (warn_slowpath_fmt) from [<c09f36ac>] (_regulator_disable+0x1a8/0x210)
[<c09f36ac>] (_regulator_disable) from [<c09f374c>] (regulator_disable+0x38/0xe8)
[<c09f374c>] (regulator_disable) from [<c0df7bac>] (ehci_ci_portpower+0x38/0xdc)
[<c0df7bac>] (ehci_ci_portpower) from [<c0db4fa4>] (ehci_port_power+0x50/0xa4)
[<c0db4fa4>] (ehci_port_power) from [<c0db5420>] (ehci_silence_controller+0x5c/0xc4)
[<c0db5420>] (ehci_silence_controller) from [<c0db7644>] (ehci_stop+0x3c/0xcc)
[<c0db7644>] (ehci_stop) from [<c0d5bdc4>] (usb_remove_hcd+0xe0/0x19c)
[<c0d5bdc4>] (usb_remove_hcd) from [<c0df7638>] (host_stop+0x38/0xa8)
[<c0df7638>] (host_stop) from [<c0df2f34>] (ci_hdrc_remove+0x44/0xe4)
...

Keeping track of the power enable state avoids the warning and traceback.

Fixes: c8679a2fb8dec ("usb: chipidea: host: add portpower override")
Cc: Michael Grzeschik <m.grzeschik@pengutronix.de>
Cc: Peter Chen <peter.chen@freescale.com>
Cc: stable@vger.kernel.org
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/usb/chipidea/host.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/chipidea/host.c b/drivers/usb/chipidea/host.c
index b45ceb91c735..48e4a5ca1835 100644
--- a/drivers/usb/chipidea/host.c
+++ b/drivers/usb/chipidea/host.c
@@ -26,6 +26,7 @@ static int (*orig_bus_suspend)(struct usb_hcd *hcd);
 
 struct ehci_ci_priv {
 	struct regulator *reg_vbus;
+	bool enabled;
 };
 
 static int ehci_ci_portpower(struct usb_hcd *hcd, int portnum, bool enable)
@@ -37,7 +38,7 @@ static int ehci_ci_portpower(struct usb_hcd *hcd, int portnum, bool enable)
 	int ret = 0;
 	int port = HCS_N_PORTS(ehci->hcs_params);
 
-	if (priv->reg_vbus) {
+	if (priv->reg_vbus && enable != priv->enabled) {
 		if (port > 1) {
 			dev_warn(dev,
 				"Not support multi-port regulator control\n");
@@ -53,6 +54,7 @@ static int ehci_ci_portpower(struct usb_hcd *hcd, int portnum, bool enable)
 				enable ? "enable" : "disable", ret);
 			return ret;
 		}
+		priv->enabled = enable;
 	}
 
 	if (enable && (ci->platdata->phy_mode == USBPHY_INTERFACE_MODE_HSIC)) {
-- 
2.17.1