usb: renesas_usbhs: modify spinlock method

Current renesas_usbhs driver was using spin_trylock to avoid
dead lock / nest lock.
But acording to CONFIG_DEBUG_SPINLOCK, it is BUG under UP environment.
This patch add usbhsg_trylock to avoid this issue.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 61 insertions, 36 deletions

diff --git a/drivers/usb/renesas_usbhs/mod_gadget.c b/drivers/usb/renesas_usbhs/mod_gadget.c
index 8c721d86bac..d027c80ab35 100644
--- a/drivers/usb/renesas_usbhs/mod_gadget.c
+++ b/drivers/usb/renesas_usbhs/mod_gadget.c
@@ -119,6 +119,35 @@ struct usbhsg_recip_handle {
 #define usbhsg_status_has(gp, b) (gp->status &   b)
 
 /*
+ *              usbhsg_trylock
+ *
+ * This driver don't use spin_try_lock
+ * to avoid warning of CONFIG_DEBUG_SPINLOCK
+ */
+static spinlock_t *usbhsg_trylock(struct usbhsg_gpriv *gpriv,
+                                  unsigned long *flags)
+{
+        spinlock_t *lock = usbhsg_gpriv_to_lock(gpriv);
+
+        /* check spin lock status
+         * to avoid deadlock/nest */
+        if (spin_is_locked(lock))
+                return NULL;
+
+        spin_lock_irqsave(lock, *flags);
+
+        return lock;
+}
+
+static void usbhsg_unlock(spinlock_t *lock, unsigned long *flags)
+{
+        if (!lock)
+                return;
+
+        spin_unlock_irqrestore(lock, *flags);
+}
+
+/*
  *              list push/pop
  */
 static void usbhsg_queue_push(struct usbhsg_uep *uep,
@@ -159,9 +188,8 @@ static int __usbhsg_queue_handler(struct usbhsg_uep *uep, int prepare)
         struct usbhsg_gpriv *gpriv = usbhsg_uep_to_gpriv(uep);
         struct device *dev = usbhsg_gpriv_to_dev(gpriv);
         struct usbhsg_request *ureq;
-        spinlock_t *lock = usbhsg_gpriv_to_lock(gpriv);
+        spinlock_t *lock;
         unsigned long flags;
-        int is_locked;
         int ret = 0;
 
         if (!uep->handler) {
@@ -179,7 +207,7 @@ static int __usbhsg_queue_handler(struct usbhsg_uep *uep, int prepare)
          *   - usb_request :: complete
          *
          * But the caller of this function need not care about spinlock.
-         * This function is using spin_trylock_irqsave for it.
+         * This function is using usbhsg_trylock for it.
          * if "is_locked" is 1, this mean this function lock it.
          * but if it is 0, this mean it is already under spin lock.
          * see also
@@ -188,7 +216,8 @@ static int __usbhsg_queue_handler(struct usbhsg_uep *uep, int prepare)
          */
 
         /******************  spin try lock *******************/
-        is_locked = spin_trylock_irqsave(lock, flags);
+        lock = usbhsg_trylock(gpriv, &flags);
+
         ureq = usbhsg_queue_get(uep);
         if (ureq) {
                 if (prepare)
@@ -196,8 +225,7 @@ static int __usbhsg_queue_handler(struct usbhsg_uep *uep, int prepare)
                 else
                         ret = uep->handler->try_run(uep, ureq);
         }
-        if (is_locked)
-                spin_unlock_irqrestore(lock, flags);
+        usbhsg_unlock(lock, &flags);
         /********************  spin unlock ******************/
 
         return ret;
@@ -228,7 +256,7 @@ static void usbhsg_queue_pop(struct usbhsg_uep *uep,
          * It mean "usb_ep_ops :: queue" which is using spinlock is called
          * under spinlock.
          *
-         * To avoid dead-lock, this driver is using spin_trylock.
+         * To avoid dead-lock, this driver is using usbhsg_trylock.
          *   CAUTION [*endpoint queue*]
          *   CAUTION [*queue handler*]
          */
@@ -811,7 +839,7 @@ static int usbhsg_ep_enable(struct usb_ep *ep,
         struct usbhsg_gpriv *gpriv = usbhsg_uep_to_gpriv(uep);
         struct usbhs_priv *priv = usbhsg_gpriv_to_priv(gpriv);
         struct usbhs_pipe *pipe;
-        spinlock_t *lock = usbhsg_gpriv_to_lock(gpriv);
+        spinlock_t *lock;
         unsigned long flags;
         int ret = -EIO;
 
@@ -823,7 +851,7 @@ static int usbhsg_ep_enable(struct usb_ep *ep,
                 return 0;
 
         /********************  spin lock ********************/
-        spin_lock_irqsave(lock, flags);
+        lock = usbhsg_trylock(gpriv, &flags);
 
         pipe = usbhs_pipe_malloc(priv, desc);
         if (pipe) {
@@ -838,7 +866,8 @@ static int usbhsg_ep_enable(struct usb_ep *ep,
 
                 ret = 0;
         }
-        spin_unlock_irqrestore(lock, flags);
+
+        usbhsg_unlock(lock, &flags);
         /********************  spin unlock ******************/
 
         return ret;
@@ -848,14 +877,16 @@ static int usbhsg_ep_disable(struct usb_ep *ep)
 {
         struct usbhsg_uep *uep = usbhsg_ep_to_uep(ep);
         struct usbhsg_gpriv *gpriv = usbhsg_uep_to_gpriv(uep);
-        spinlock_t *lock = usbhsg_gpriv_to_lock(gpriv);
+        spinlock_t *lock;
         unsigned long flags;
         int ret;
 
         /********************  spin lock ********************/
-        spin_lock_irqsave(lock, flags);
+        lock = usbhsg_trylock(gpriv, &flags);
+
         ret = usbhsg_pipe_disable(uep);
-        spin_unlock_irqrestore(lock, flags);
+
+        usbhsg_unlock(lock, &flags);
         /********************  spin unlock ******************/
 
         return ret;
@@ -890,10 +921,9 @@ static int usbhsg_ep_queue(struct usb_ep *ep, struct usb_request *req,
         struct usbhsg_gpriv *gpriv = usbhsg_uep_to_gpriv(uep);
         struct usbhsg_request *ureq = usbhsg_req_to_ureq(req);
         struct usbhs_pipe *pipe = usbhsg_uep_to_pipe(uep);
-        spinlock_t *lock = usbhsg_gpriv_to_lock(gpriv);
+        spinlock_t *lock;
         unsigned long flags;
         int ret = 0;
-        int is_locked;
 
         /*
          * CAUTION [*endpoint queue*]
@@ -904,7 +934,7 @@ static int usbhsg_ep_queue(struct usb_ep *ep, struct usb_request *req,
          * it is already under spinlock on this driver.
          * but it is called frm usb driver, this function should call spinlock.
          *
-         * This function is using spin_trylock_irqsave to solve this issue.
+         * This function is using usbshg_trylock to solve this issue.
          * if "is_locked" is 1, this mean this function lock it.
          * but if it is 0, this mean it is already under spin lock.
          * see also
@@ -913,7 +943,7 @@ static int usbhsg_ep_queue(struct usb_ep *ep, struct usb_request *req,
          */
 
         /********************  spin lock ********************/
-        is_locked = spin_trylock_irqsave(lock, flags);
+        lock = usbhsg_trylock(gpriv, &flags);
 
         /* param check */
         if (usbhsg_is_not_connected(gpriv)      ||
@@ -923,8 +953,7 @@ static int usbhsg_ep_queue(struct usb_ep *ep, struct usb_request *req,
         else
                 usbhsg_queue_push(uep, ureq);
 
-        if (is_locked)
-                spin_unlock_irqrestore(lock, flags);
+        usbhsg_unlock(lock, &flags);
         /********************  spin unlock ******************/
 
         usbhsg_queue_prepare(uep);
@@ -937,9 +966,8 @@ static int usbhsg_ep_dequeue(struct usb_ep *ep, struct usb_request *req)
         struct usbhsg_uep *uep = usbhsg_ep_to_uep(ep);
         struct usbhsg_request *ureq = usbhsg_req_to_ureq(req);
         struct usbhsg_gpriv *gpriv = usbhsg_uep_to_gpriv(uep);
-        spinlock_t *lock = usbhsg_gpriv_to_lock(gpriv);
+        spinlock_t *lock;
         unsigned long flags;
-        int is_locked;
 
         /*
          * see
@@ -949,12 +977,11 @@ static int usbhsg_ep_dequeue(struct usb_ep *ep, struct usb_request *req)
          */
 
         /********************  spin lock ********************/
-        is_locked = spin_trylock_irqsave(lock, flags);
+        lock = usbhsg_trylock(gpriv, &flags);
 
         usbhsg_queue_pop(uep, ureq, -ECONNRESET);
 
-        if (is_locked)
-                spin_unlock_irqrestore(lock, flags);
+        usbhsg_unlock(lock, &flags);
         /********************  spin unlock ******************/
 
         return 0;
@@ -966,10 +993,9 @@ static int __usbhsg_ep_set_halt_wedge(struct usb_ep *ep, int halt, int wedge)
         struct usbhs_pipe *pipe = usbhsg_uep_to_pipe(uep);
         struct usbhsg_gpriv *gpriv = usbhsg_uep_to_gpriv(uep);
         struct device *dev = usbhsg_gpriv_to_dev(gpriv);
-        spinlock_t *lock = usbhsg_gpriv_to_lock(gpriv);
+        spinlock_t *lock;
         unsigned long flags;
         int ret = -EAGAIN;
-        int is_locked;
 
         /*
          * see
@@ -979,7 +1005,7 @@ static int __usbhsg_ep_set_halt_wedge(struct usb_ep *ep, int halt, int wedge)
          */
 
         /********************  spin lock ********************/
-        is_locked = spin_trylock_irqsave(lock, flags);
+        lock = usbhsg_trylock(gpriv, &flags);
         if (!usbhsg_queue_get(uep)) {
 
                 dev_dbg(dev, "set halt %d (pipe %d)\n",
@@ -998,8 +1024,7 @@ static int __usbhsg_ep_set_halt_wedge(struct usb_ep *ep, int halt, int wedge)
                 ret = 0;
         }
 
-        if (is_locked)
-                spin_unlock_irqrestore(lock, flags);
+        usbhsg_unlock(lock, &flags);
         /********************  spin unlock ******************/
 
         return ret;
@@ -1038,11 +1063,11 @@ static int usbhsg_try_start(struct usbhs_priv *priv, u32 status)
         struct usbhsg_uep *dcp = usbhsg_gpriv_to_dcp(gpriv);
         struct usbhs_mod *mod = usbhs_mod_get_current(priv);
         struct device *dev = usbhs_priv_to_dev(priv);
-        spinlock_t *lock = usbhsg_gpriv_to_lock(gpriv);
+        spinlock_t *lock;
         unsigned long flags;
 
         /********************  spin lock ********************/
-        spin_lock_irqsave(lock, flags);
+        lock = usbhsg_trylock(gpriv, &flags);
 
         /*
          * enable interrupt and systems if ready
@@ -1083,7 +1108,7 @@ static int usbhsg_try_start(struct usbhs_priv *priv, u32 status)
         usbhs_irq_callback_update(priv, mod);
 
 usbhsg_try_start_unlock:
-        spin_unlock_irqrestore(lock, flags);
+        usbhsg_unlock(lock, &flags);
         /********************  spin unlock ********************/
 
         return 0;
@@ -1095,11 +1120,11 @@ static int usbhsg_try_stop(struct usbhs_priv *priv, u32 status)
         struct usbhs_mod *mod = usbhs_mod_get_current(priv);
         struct usbhsg_uep *dcp = usbhsg_gpriv_to_dcp(gpriv);
         struct device *dev = usbhs_priv_to_dev(priv);
-        spinlock_t *lock = usbhsg_gpriv_to_lock(gpriv);
+        spinlock_t *lock;
         unsigned long flags;
 
         /********************  spin lock ********************/
-        spin_lock_irqsave(lock, flags);
+        lock = usbhsg_trylock(gpriv, &flags);
 
         /*
          * disable interrupt and systems if 1st try
@@ -1127,7 +1152,7 @@ static int usbhsg_try_stop(struct usbhs_priv *priv, u32 status)
         usbhs_sys_function_ctrl(priv, 0);
         usbhs_sys_usb_ctrl(priv, 0);
 
-        spin_unlock_irqrestore(lock, flags);
+        usbhsg_unlock(lock, &flags);
         /********************  spin unlock ********************/
 
         if (gpriv->driver &&
@@ -1139,7 +1164,7 @@ static int usbhsg_try_stop(struct usbhs_priv *priv, u32 status)
         return 0;
 
 usbhsg_try_stop_unlock:
-        spin_unlock_irqrestore(lock, flags);
+        usbhsg_unlock(lock, &flags);
 
         return 0;
 }