usb: gadget: udc: core: Offload usb_udc_vbus_handler processing
usb_udc_vbus_handler() can be invoked from interrupt context by irq
handlers of the gadget drivers, however, usb_udc_connect_control() has
to run in non-atomic context due to the following:
a. Some of the gadget driver implementations expect the ->pullup
callback to be invoked in non-atomic context.
b. usb_gadget_disconnect() acquires udc_lock which is a mutex.
Hence offload invocation of usb_udc_connect_control()
to workqueue.
UDC should not be pulled up unless gadget driver is bound. The new flag
"allow_connect" is now set by gadget_bind_driver() and cleared by
gadget_unbind_driver(). This prevents work item to pull up the gadget
even if queued when the gadget driver is already unbound.
Cc: stable@vger.kernel.org
Fixes: 1016fc0c09
("USB: gadget: Fix obscure lockdep violation for udc_mutex")
Signed-off-by: Badhri Jagan Sridharan <badhri@google.com>
Reviewed-by: Alan Stern <stern@rowland.harvard.edu>
Message-ID: <20230609010227.978661-1-badhri@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
parent
92c9c3baad
commit
50966da807
|
@ -37,6 +37,9 @@ 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.
|
||||
* @allow_connect: Indicates whether UDC is allowed to be pulled up.
|
||||
* Set/cleared by gadget_(un)bind_driver() after gadget driver is bound or
|
||||
* unbound.
|
||||
*
|
||||
* This represents the internal data structure which is used by the UDC-class
|
||||
* to hold information about udc driver and gadget together.
|
||||
|
@ -48,6 +51,8 @@ struct usb_udc {
|
|||
struct list_head list;
|
||||
bool vbus;
|
||||
bool started;
|
||||
bool allow_connect;
|
||||
struct work_struct vbus_work;
|
||||
};
|
||||
|
||||
static struct class *udc_class;
|
||||
|
@ -706,7 +711,7 @@ int usb_gadget_connect(struct usb_gadget *gadget)
|
|||
goto out;
|
||||
}
|
||||
|
||||
if (gadget->deactivated) {
|
||||
if (gadget->deactivated || !gadget->udc->allow_connect) {
|
||||
/*
|
||||
* If gadget is deactivated we only save new state.
|
||||
* Gadget will be connected automatically after activation.
|
||||
|
@ -1086,6 +1091,13 @@ static void usb_udc_connect_control(struct usb_udc *udc)
|
|||
usb_gadget_disconnect(udc->gadget);
|
||||
}
|
||||
|
||||
static void vbus_event_work(struct work_struct *work)
|
||||
{
|
||||
struct usb_udc *udc = container_of(work, struct usb_udc, vbus_work);
|
||||
|
||||
usb_udc_connect_control(udc);
|
||||
}
|
||||
|
||||
/**
|
||||
* usb_udc_vbus_handler - updates the udc core vbus status, and try to
|
||||
* connect or disconnect gadget
|
||||
|
@ -1094,6 +1106,14 @@ static void usb_udc_connect_control(struct usb_udc *udc)
|
|||
*
|
||||
* The udc driver calls it when it wants to connect or disconnect gadget
|
||||
* according to vbus status.
|
||||
*
|
||||
* This function can be invoked from interrupt context by irq handlers of
|
||||
* the gadget drivers, however, usb_udc_connect_control() has to run in
|
||||
* non-atomic context due to the following:
|
||||
* a. Some of the gadget driver implementations expect the ->pullup
|
||||
* callback to be invoked in non-atomic context.
|
||||
* b. usb_gadget_disconnect() acquires udc_lock which is a mutex.
|
||||
* Hence offload invocation of usb_udc_connect_control() to workqueue.
|
||||
*/
|
||||
void usb_udc_vbus_handler(struct usb_gadget *gadget, bool status)
|
||||
{
|
||||
|
@ -1101,7 +1121,7 @@ void usb_udc_vbus_handler(struct usb_gadget *gadget, bool status)
|
|||
|
||||
if (udc) {
|
||||
udc->vbus = status;
|
||||
usb_udc_connect_control(udc);
|
||||
schedule_work(&udc->vbus_work);
|
||||
}
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(usb_udc_vbus_handler);
|
||||
|
@ -1328,6 +1348,7 @@ int usb_add_gadget(struct usb_gadget *gadget)
|
|||
mutex_lock(&udc_lock);
|
||||
list_add_tail(&udc->list, &udc_list);
|
||||
mutex_unlock(&udc_lock);
|
||||
INIT_WORK(&udc->vbus_work, vbus_event_work);
|
||||
|
||||
ret = device_add(&udc->dev);
|
||||
if (ret)
|
||||
|
@ -1459,6 +1480,7 @@ void usb_del_gadget(struct usb_gadget *gadget)
|
|||
flush_work(&gadget->work);
|
||||
device_del(&gadget->dev);
|
||||
ida_free(&gadget_id_numbers, gadget->id_number);
|
||||
cancel_work_sync(&udc->vbus_work);
|
||||
device_unregister(&udc->dev);
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(usb_del_gadget);
|
||||
|
@ -1527,6 +1549,7 @@ static int gadget_bind_driver(struct device *dev)
|
|||
if (ret)
|
||||
goto err_start;
|
||||
usb_gadget_enable_async_callbacks(udc);
|
||||
udc->allow_connect = true;
|
||||
usb_udc_connect_control(udc);
|
||||
|
||||
kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);
|
||||
|
@ -1558,6 +1581,8 @@ static void gadget_unbind_driver(struct device *dev)
|
|||
|
||||
kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);
|
||||
|
||||
udc->allow_connect = false;
|
||||
cancel_work_sync(&udc->vbus_work);
|
||||
usb_gadget_disconnect(gadget);
|
||||
usb_gadget_disable_async_callbacks(udc);
|
||||
if (gadget->irq)
|
||||
|
|
Loading…
Reference in New Issue