[PATCH 2/2] usb: chipidea: udc: protect usb interrupt enable

[Peter Chen]

From: Jun Li <jun...@nxp.com>

We hit the problem with below sequence:
- ci_udc_vbus_session() update vbus_active flag and ci->driver
is valid,
- before calling the ci_hdrc_gadget_connect(),
usb_gadget_udc_stop() is called by application remove gadget
driver,
- ci_udc_vbus_session() will contine do ci_hdrc_gadget_connect() as
gadget_ready is 1, so udc interrupt is enabled, but ci->driver is
NULL.
- USB connection irq generated but ci->driver is NULL.

As udc irq only should be enabled when gadget driver is binded, so
add spinlock to protect the usb irq enable for vbus session handling.

Signed-off-by: Jun Li <jun...@nxp.com>
Signed-off-by: Peter Chen <peter.c...@nxp.com>
---
Jun, I changed a little for your patch, please check if it is OK.

 drivers/usb/chipidea/udc.c | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/drivers/usb/chipidea/udc.c b/drivers/usb/chipidea/udc.c
index 59f31c7a7136..59c34ce6b450 100644
--- a/drivers/usb/chipidea/udc.c
+++ b/drivers/usb/chipidea/udc.c
@@ -1530,13 +1530,18 @@ static const struct usb_ep_ops usb_ep_ops = {
 static void ci_hdrc_gadget_connect(struct usb_gadget *_gadget, int is_active)
 {
        struct ci_hdrc *ci = container_of(_gadget, struct ci_hdrc, gadget);
+       unsigned long flags;
 
        if (is_active) {
                pm_runtime_get_sync(&_gadget->dev);
                hw_device_reset(ci);
-               hw_device_state(ci, ci->ep0out->qh.dma);
-               usb_gadget_set_state(_gadget, USB_STATE_POWERED);
-               usb_udc_vbus_handler(_gadget, true);
+               spin_lock_irqsave(&ci->lock, flags);
+               if (ci->driver) {
+                       hw_device_state(ci, ci->ep0out->qh.dma);
+                       usb_gadget_set_state(_gadget, USB_STATE_POWERED);
+                       usb_udc_vbus_handler(_gadget, true);
+               }
+               spin_unlock_irqrestore(&ci->lock, flags);
        } else {
                usb_udc_vbus_handler(_gadget, false);
                if (ci->driver)
@@ -1555,19 +1560,16 @@ static int ci_udc_vbus_session(struct usb_gadget 
*_gadget, int is_active)
 {
        struct ci_hdrc *ci = container_of(_gadget, struct ci_hdrc, gadget);
        unsigned long flags;
-       int gadget_ready = 0;
 
        spin_lock_irqsave(&ci->lock, flags);
        ci->vbus_active = is_active;
-       if (ci->driver)
-               gadget_ready = 1;
        spin_unlock_irqrestore(&ci->lock, flags);
 
        if (ci->usb_phy)
                usb_phy_set_charger_state(ci->usb_phy, is_active ?
                        USB_CHARGER_PRESENT : USB_CHARGER_ABSENT);
 
-       if (gadget_ready)
+       if (ci->driver)
                ci_hdrc_gadget_connect(_gadget, is_active);
 
        return 0;
@@ -1827,6 +1829,7 @@ static int ci_udc_stop(struct usb_gadget *gadget)
        unsigned long flags;
 
        spin_lock_irqsave(&ci->lock, flags);
+       ci->driver = NULL;
 
        if (ci->vbus_active) {
                hw_device_state(ci, 0);
@@ -1839,7 +1842,6 @@ static int ci_udc_stop(struct usb_gadget *gadget)
                pm_runtime_put(&ci->gadget.dev);
        }
 
-       ci->driver = NULL;
        spin_unlock_irqrestore(&ci->lock, flags);
 
        ci_udc_stop_for_otg_fsm(ci);
-- 
2.17.1