Commit f22e9b67 authored by Francesco Dolcini's avatar Francesco Dolcini Committed by Greg Kroah-Hartman
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Revert "usb: gadget: udc: core: Invoke usb_gadget_connect only when started" 



This reverts commit 0db213ea.

It introduces an issues with configuring the USB gadget hangs forever
on multiple Qualcomm and NXP i.MX SoC at least.

Cc: stable@vger.kernel.org
Fixes: 0db213ea ("usb: gadget: udc: core: Invoke usb_gadget_connect only when started")
Reported-by: default avatarStephan Gerhold <stephan@gerhold.net>
Reported-by: default avatarFrancesco Dolcini <francesco.dolcini@toradex.com>
Link: https://lore.kernel.org/all/ZF4BvgsOyoKxdPFF@francesco-nb.int.toradex.com/


Signed-off-by: default avatarFrancesco Dolcini <francesco.dolcini@toradex.com>
Link: https://lore.kernel.org/r/20230512131435.205464-3-francesco@dolcini.it


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 5e161721

drivers/usb/gadget/udc/core.c

+44 −104
Original line number Diff line number Diff line
@@ -37,10 +37,6 @@ static const struct bus_type gadget_bus_type; 
 * @vbus: for udcs who care about vbus status, this value is real vbus status;

 * for udcs who do not care about vbus status, this value is always true

 * @started: the UDC's started state. True if the UDC had started.

 * @connect_lock: protects udc->vbus, udc->started, gadget->connect, gadget->deactivate related

 * functions. usb_gadget_connect_locked, usb_gadget_disconnect_locked,

 * usb_udc_connect_control_locked, usb_gadget_udc_start_locked, usb_gadget_udc_stop_locked are

 * called with this lock held.

 *

 * This represents the internal data structure which is used by the UDC-class

 * to hold information about udc driver and gadget together.
@@ -52,7 +48,6 @@ struct usb_udc { 
	struct list_head		list;

	bool				vbus;

	bool				started;

	struct mutex			connect_lock;

};



static struct class *udc_class;
@@ -692,9 +687,17 @@ int usb_gadget_vbus_disconnect(struct usb_gadget *gadget) 
}

EXPORT_SYMBOL_GPL(usb_gadget_vbus_disconnect);



/* Internal version of usb_gadget_connect needs to be called with connect_lock held. */

static int usb_gadget_connect_locked(struct usb_gadget *gadget)

	__must_hold(&gadget->udc->connect_lock)

/**

 * usb_gadget_connect - software-controlled connect to USB host

 * @gadget:the peripheral being connected

 *

 * Enables the D+ (or potentially D-) pullup.  The host will start

 * enumerating this gadget when the pullup is active and a VBUS session

 * is active (the link is powered).

 *

 * Returns zero on success, else negative errno.

 */

int usb_gadget_connect(struct usb_gadget *gadget)

{

	int ret = 0;
@@ -703,12 +706,10 @@ static int usb_gadget_connect_locked(struct usb_gadget *gadget) 
		goto out;

	}



	if (gadget->deactivated || !gadget->udc->started) {

	if (gadget->deactivated) {

		/*

		 * If gadget is deactivated we only save new state.

		 * Gadget will be connected automatically after activation.

		 *

		 * udc first needs to be started before gadget can be pulled up.

		 */

		gadget->connected = true;

		goto out;
@@ -723,32 +724,22 @@ static int usb_gadget_connect_locked(struct usb_gadget *gadget) 


	return ret;

}

EXPORT_SYMBOL_GPL(usb_gadget_connect);



/**

 * usb_gadget_connect - software-controlled connect to USB host

 * @gadget:the peripheral being connected

 * usb_gadget_disconnect - software-controlled disconnect from USB host

 * @gadget:the peripheral being disconnected

 *

 * Enables the D+ (or potentially D-) pullup.  The host will start

 * enumerating this gadget when the pullup is active and a VBUS session

 * is active (the link is powered).

 * Disables the D+ (or potentially D-) pullup, which the host may see

 * as a disconnect (when a VBUS session is active).  Not all systems

 * support software pullup controls.

 *

 * Following a successful disconnect, invoke the ->disconnect() callback

 * for the current gadget driver so that UDC drivers don't need to.

 *

 * Returns zero on success, else negative errno.

 */

int usb_gadget_connect(struct usb_gadget *gadget)

{

	int ret;



	mutex_lock(&gadget->udc->connect_lock);

	ret = usb_gadget_connect_locked(gadget);

	mutex_unlock(&gadget->udc->connect_lock);



	return ret;

}

EXPORT_SYMBOL_GPL(usb_gadget_connect);



/* Internal version of usb_gadget_disconnect needs to be called with connect_lock held. */

static int usb_gadget_disconnect_locked(struct usb_gadget *gadget)

	__must_hold(&gadget->udc->connect_lock)

int usb_gadget_disconnect(struct usb_gadget *gadget)

{

	int ret = 0;
@@ -760,12 +751,10 @@ static int usb_gadget_disconnect_locked(struct usb_gadget *gadget) 
	if (!gadget->connected)

		goto out;



	if (gadget->deactivated || !gadget->udc->started) {

	if (gadget->deactivated) {

		/*

		 * If gadget is deactivated we only save new state.

		 * Gadget will stay disconnected after activation.

		 *

		 * udc should have been started before gadget being pulled down.

		 */

		gadget->connected = false;

		goto out;
@@ -785,30 +774,6 @@ static int usb_gadget_disconnect_locked(struct usb_gadget *gadget) 


	return ret;

}



/**

 * usb_gadget_disconnect - software-controlled disconnect from USB host

 * @gadget:the peripheral being disconnected

 *

 * Disables the D+ (or potentially D-) pullup, which the host may see

 * as a disconnect (when a VBUS session is active).  Not all systems

 * support software pullup controls.

 *

 * Following a successful disconnect, invoke the ->disconnect() callback

 * for the current gadget driver so that UDC drivers don't need to.

 *

 * Returns zero on success, else negative errno.

 */

int usb_gadget_disconnect(struct usb_gadget *gadget)

{

	int ret;



	mutex_lock(&gadget->udc->connect_lock);

	ret = usb_gadget_disconnect_locked(gadget);

	mutex_unlock(&gadget->udc->connect_lock);



	return ret;

}

EXPORT_SYMBOL_GPL(usb_gadget_disconnect);



/**
@@ -829,11 +794,10 @@ int usb_gadget_deactivate(struct usb_gadget *gadget) 
	if (gadget->deactivated)

		goto out;



	mutex_lock(&gadget->udc->connect_lock);

	if (gadget->connected) {

		ret = usb_gadget_disconnect_locked(gadget);

		ret = usb_gadget_disconnect(gadget);

		if (ret)

			goto unlock;

			goto out;



		/*

		 * If gadget was being connected before deactivation, we want
@@ -843,8 +807,6 @@ int usb_gadget_deactivate(struct usb_gadget *gadget) 
	}

	gadget->deactivated = true;



unlock:

	mutex_unlock(&gadget->udc->connect_lock);

out:

	trace_usb_gadget_deactivate(gadget, ret);
@@ -868,7 +830,6 @@ int usb_gadget_activate(struct usb_gadget *gadget) 
	if (!gadget->deactivated)

		goto out;



	mutex_lock(&gadget->udc->connect_lock);

	gadget->deactivated = false;



	/*
@@ -876,8 +837,7 @@ int usb_gadget_activate(struct usb_gadget *gadget) 
	 * while it was being deactivated, we call usb_gadget_connect().

	 */

	if (gadget->connected)

		ret = usb_gadget_connect_locked(gadget);

	mutex_unlock(&gadget->udc->connect_lock);

		ret = usb_gadget_connect(gadget);



out:

	trace_usb_gadget_activate(gadget, ret);
@@ -1118,13 +1078,12 @@ EXPORT_SYMBOL_GPL(usb_gadget_set_state); 


/* ------------------------------------------------------------------------- */



/* Acquire connect_lock before calling this function. */

static void usb_udc_connect_control_locked(struct usb_udc *udc) __must_hold(&udc->connect_lock)

static void usb_udc_connect_control(struct usb_udc *udc)

{

	if (udc->vbus && udc->started)

		usb_gadget_connect_locked(udc->gadget);

	if (udc->vbus)

		usb_gadget_connect(udc->gadget);

	else

		usb_gadget_disconnect_locked(udc->gadget);

		usb_gadget_disconnect(udc->gadget);

}



/**
@@ -1140,12 +1099,10 @@ void usb_udc_vbus_handler(struct usb_gadget *gadget, bool status) 
{

	struct usb_udc *udc = gadget->udc;



	mutex_lock(&udc->connect_lock);

	if (udc) {

		udc->vbus = status;

		usb_udc_connect_control_locked(udc);

		usb_udc_connect_control(udc);

	}

	mutex_unlock(&udc->connect_lock);

}

EXPORT_SYMBOL_GPL(usb_udc_vbus_handler);
@@ -1167,7 +1124,7 @@ void usb_gadget_udc_reset(struct usb_gadget *gadget, 
EXPORT_SYMBOL_GPL(usb_gadget_udc_reset);



/**

 * usb_gadget_udc_start_locked - tells usb device controller to start up

 * usb_gadget_udc_start - tells usb device controller to start up

 * @udc: The UDC to be started

 *

 * This call is issued by the UDC Class driver when it's about
@@ -1178,11 +1135,8 @@ EXPORT_SYMBOL_GPL(usb_gadget_udc_reset); 
 * necessary to have it powered on.

 *

 * Returns zero on success, else negative errno.

 *

 * Caller should acquire connect_lock before invoking this function.

 */

static inline int usb_gadget_udc_start_locked(struct usb_udc *udc)

	__must_hold(&udc->connect_lock)

static inline int usb_gadget_udc_start(struct usb_udc *udc)

{

	int ret;
@@ -1199,7 +1153,7 @@ static inline int usb_gadget_udc_start_locked(struct usb_udc *udc) 
}



/**

 * usb_gadget_udc_stop_locked - tells usb device controller we don't need it anymore

 * usb_gadget_udc_stop - tells usb device controller we don't need it anymore

 * @udc: The UDC to be stopped

 *

 * This call is issued by the UDC Class driver after calling
@@ -1208,11 +1162,8 @@ static inline int usb_gadget_udc_start_locked(struct usb_udc *udc) 
 * The details are implementation specific, but it can go as

 * far as powering off UDC completely and disable its data

 * line pullups.

 *

 * Caller should acquire connect lock before invoking this function.

 */

static inline void usb_gadget_udc_stop_locked(struct usb_udc *udc)

	__must_hold(&udc->connect_lock)

static inline void usb_gadget_udc_stop(struct usb_udc *udc)

{

	if (!udc->started) {

		dev_err(&udc->dev, "UDC had already stopped\n");
@@ -1371,7 +1322,6 @@ int usb_add_gadget(struct usb_gadget *gadget) 


	udc->gadget = gadget;

	gadget->udc = udc;

	mutex_init(&udc->connect_lock);



	udc->started = false;
@@ -1573,15 +1523,11 @@ static int gadget_bind_driver(struct device *dev) 
	if (ret)

		goto err_bind;



	mutex_lock(&udc->connect_lock);

	ret = usb_gadget_udc_start_locked(udc);

	if (ret) {

		mutex_unlock(&udc->connect_lock);

	ret = usb_gadget_udc_start(udc);

	if (ret)

		goto err_start;

	}

	usb_gadget_enable_async_callbacks(udc);

	usb_udc_connect_control_locked(udc);

	mutex_unlock(&udc->connect_lock);

	usb_udc_connect_control(udc);



	kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);

	return 0;
@@ -1612,14 +1558,12 @@ static void gadget_unbind_driver(struct device *dev) 


	kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);



	mutex_lock(&udc->connect_lock);

	usb_gadget_disconnect_locked(gadget);

	usb_gadget_disconnect(gadget);

	usb_gadget_disable_async_callbacks(udc);

	if (gadget->irq)

		synchronize_irq(gadget->irq);

	udc->driver->unbind(gadget);

	usb_gadget_udc_stop_locked(udc);

	mutex_unlock(&udc->connect_lock);

	usb_gadget_udc_stop(udc);



	mutex_lock(&udc_lock);

	driver->is_bound = false;
@@ -1705,15 +1649,11 @@ static ssize_t soft_connect_store(struct device *dev, 
	}



	if (sysfs_streq(buf, "connect")) {

		mutex_lock(&udc->connect_lock);

		usb_gadget_udc_start_locked(udc);

		usb_gadget_connect_locked(udc->gadget);

		mutex_unlock(&udc->connect_lock);

		usb_gadget_udc_start(udc);

		usb_gadget_connect(udc->gadget);

	} else if (sysfs_streq(buf, "disconnect")) {

		mutex_lock(&udc->connect_lock);

		usb_gadget_disconnect_locked(udc->gadget);

		usb_gadget_udc_stop_locked(udc);

		mutex_unlock(&udc->connect_lock);

		usb_gadget_disconnect(udc->gadget);

		usb_gadget_udc_stop(udc);

	} else {

		dev_err(dev, "unsupported command '%s'\n", buf);

		ret = -EINVAL;