From: Francesco Dolcini <francesco.dolcini@toradex.com>
Date: Fri, 12 May 2023 15:14:35 +0200
Subject: [PATCH] Revert "usb: gadget: udc: core: Invoke usb_gadget_connect
only when started"
References: bsc#1012628
Patch-mainline: 6.3.4
Git-commit: f22e9b67f19ccc73de1ae04375d4b30684e261f8
commit f22e9b67f19ccc73de1ae04375d4b30684e261f8 upstream.
This reverts commit 0db213ea8eed5534a5169e807f28103cbc9d23df.
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: 0db213ea8eed ("usb: gadget: udc: core: Invoke usb_gadget_connect only when started")
Reported-by: Stephan Gerhold <stephan@gerhold.net>
Reported-by: Francesco Dolcini <francesco.dolcini@toradex.com>
Link: https://lore.kernel.org/all/ZF4BvgsOyoKxdPFF@francesco-nb.int.toradex.com/
Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
Link: https://lore.kernel.org/r/20230512131435.205464-3-francesco@dolcini.it
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
drivers/usb/gadget/udc/core.c | 148 ++++++++++------------------------
1 file changed, 44 insertions(+), 104 deletions(-)
diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c
index ebb2b839..23b0629a 100644
--- a/drivers/usb/gadget/udc/core.c
+++ b/drivers/usb/gadget/udc/core.c
@@ -37,10 +37,6 @@ static 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;
@@ -665,9 +660,17 @@ 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;
@@ -676,12 +679,10 @@ 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;
@@ -696,32 +697,22 @@ 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;
@@ -733,12 +724,10 @@ 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;
@@ -758,30 +747,6 @@ 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);
/**
@@ -802,11 +767,10 @@ 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
@@ -816,8 +780,6 @@ 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);
@@ -841,7 +803,6 @@ int usb_gadget_activate(struct usb_gadget *gadget)
if (!gadget->deactivated)
goto out;
- mutex_lock(&gadget->udc->connect_lock);
gadget->deactivated = false;
/*
@@ -849,8 +810,7 @@ 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);
@@ -1091,13 +1051,12 @@ 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);
}
/**
@@ -1113,12 +1072,10 @@ 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);
@@ -1140,7 +1097,7 @@ 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
@@ -1151,11 +1108,8 @@ 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;
@@ -1172,7 +1126,7 @@ 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
@@ -1181,11 +1135,8 @@ 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");
@@ -1344,7 +1295,6 @@ int usb_add_gadget(struct usb_gadget *gadget)
udc->gadget = gadget;
gadget->udc = udc;
- mutex_init(&udc->connect_lock);
udc->started = false;
@@ -1546,15 +1496,11 @@ 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;
@@ -1585,14 +1531,12 @@ 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;
@@ -1678,15 +1622,11 @@ 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;
--
2.35.3