usb: mtu3: implement udc_async_callbacks of gadget operation

Implement udc_async_callbacks hook function to avoid a race when unnbinding
gadget drivers, refer to:
7dc0c55e9f30 ('USB: UDC core: Add udc_async_callbacks gadget op')

Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Link: https://lore.kernel.org/r/20220609074233.15532-2-chunfeng.yun@mediatek.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/mtu3/mtu3.h b/drivers/usb/mtu3/mtu3.h
index 022bbdc..8408e1b 100644 (file)
--- a/drivers/usb/mtu3/mtu3.h
+++ b/drivers/usb/mtu3/mtu3.h
@@ -357,6 +357,7 @@ struct mtu3 {
        unsigned delayed_status:1;
        unsigned gen2cp:1;
        unsigned connected:1;
+       unsigned async_callbacks:1;
 
        u8 address;
        u8 test_mode_nr;

diff --git a/drivers/usb/mtu3/mtu3_gadget.c b/drivers/usb/mtu3/mtu3_gadget.c
index d57cea6..30999b4 100644 (file)
--- a/drivers/usb/mtu3/mtu3_gadget.c
+++ b/drivers/usb/mtu3/mtu3_gadget.c
@@ -592,6 +592,18 @@ mtu3_gadget_set_speed(struct usb_gadget *g, enum usb_device_speed speed)
        spin_unlock_irqrestore(&mtu->lock, flags);
 }
 
+static void mtu3_gadget_async_callbacks(struct usb_gadget *g, bool enable)
+{
+       struct mtu3 *mtu = gadget_to_mtu3(g);
+       unsigned long flags;
+
+       dev_dbg(mtu->dev, "%s %s\n", __func__, enable ? "en" : "dis");
+
+       spin_lock_irqsave(&mtu->lock, flags);
+       mtu->async_callbacks = enable;
+       spin_unlock_irqrestore(&mtu->lock, flags);
+}
+
 static const struct usb_gadget_ops mtu3_gadget_ops = {
        .get_frame = mtu3_gadget_get_frame,
        .wakeup = mtu3_gadget_wakeup,
@@ -600,6 +612,7 @@ static const struct usb_gadget_ops mtu3_gadget_ops = {
        .udc_start = mtu3_gadget_start,
        .udc_stop = mtu3_gadget_stop,
        .udc_set_speed = mtu3_gadget_set_speed,
+       .udc_async_callbacks = mtu3_gadget_async_callbacks,
 };
 
 static void mtu3_state_reset(struct mtu3 *mtu)
@@ -697,7 +710,7 @@ void mtu3_gadget_cleanup(struct mtu3 *mtu)
 void mtu3_gadget_resume(struct mtu3 *mtu)
 {
        dev_dbg(mtu->dev, "gadget RESUME\n");
-       if (mtu->gadget_driver && mtu->gadget_driver->resume) {
+       if (mtu->async_callbacks && mtu->gadget_driver && mtu->gadget_driver->resume) {
                spin_unlock(&mtu->lock);
                mtu->gadget_driver->resume(&mtu->g);
                spin_lock(&mtu->lock);
@@ -708,7 +721,7 @@ void mtu3_gadget_resume(struct mtu3 *mtu)
 void mtu3_gadget_suspend(struct mtu3 *mtu)
 {
        dev_dbg(mtu->dev, "gadget SUSPEND\n");
-       if (mtu->gadget_driver && mtu->gadget_driver->suspend) {
+       if (mtu->async_callbacks && mtu->gadget_driver && mtu->gadget_driver->suspend) {
                spin_unlock(&mtu->lock);
                mtu->gadget_driver->suspend(&mtu->g);
                spin_lock(&mtu->lock);
@@ -719,7 +732,7 @@ void mtu3_gadget_suspend(struct mtu3 *mtu)
 void mtu3_gadget_disconnect(struct mtu3 *mtu)
 {
        dev_dbg(mtu->dev, "gadget DISCONNECT\n");
-       if (mtu->gadget_driver && mtu->gadget_driver->disconnect) {
+       if (mtu->async_callbacks && mtu->gadget_driver && mtu->gadget_driver->disconnect) {
                spin_unlock(&mtu->lock);
                mtu->gadget_driver->disconnect(&mtu->g);
                spin_lock(&mtu->lock);

diff --git a/drivers/usb/mtu3/mtu3_gadget_ep0.c b/drivers/usb/mtu3/mtu3_gadget_ep0.c
index 0ca4721..7e70135 100644 (file)
--- a/drivers/usb/mtu3/mtu3_gadget_ep0.c
+++ b/drivers/usb/mtu3/mtu3_gadget_ep0.c
@@ -66,7 +66,7 @@ __acquires(mtu->lock)
 {
        int ret;
 
-       if (!mtu->gadget_driver)
+       if (!mtu->gadget_driver || !mtu->async_callbacks)
                return -EOPNOTSUPP;
 
        spin_unlock(&mtu->lock);