rtl8712: pwrctrl_priv: Replace semaphore lock with mutex

The semaphore 'lock' in 'pwrctrl_priv' is used as a simple mutex, so it
should be written as one. Semaphores are going away in the future.
_enter_pwrlock was using down_interruptible(), so the lock could be broken
by sending a signal. This could be a bug, because nothing checks the return
code here. Hence, using mutex_lock instead of the interruptible version.
Removing the now unused _enter_pwrlock and _down_sema.

Signed-off-by: Binoy Jayan <[e-mail]>
Reviewed-by: Arnd Bergmann <[e-mail]>
Tested-by: Larry Finger <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/staging/rtl8712/osdep_service.h

···
 		spin_lock_init(&((pqueue)->lock));	\
 	} while (0)
 
-static inline u32 _down_sema(struct semaphore *sema)
-{
-	if (down_interruptible(sema))
-		return _FAIL;
-	return _SUCCESS;
-}
-
 static inline u32 end_of_queue_search(struct list_head *head,
 		struct list_head *plist)
 {

drivers/staging/rtl8712/rtl8712_cmd.c

···
 		 */
 		if (padapter->pwrctrlpriv.pwr_mode > PS_MODE_ACTIVE) {
 			padapter->pwrctrlpriv.pwr_mode = PS_MODE_ACTIVE;
-			_enter_pwrlock(&(padapter->pwrctrlpriv.lock));
+			mutex_lock(&padapter->pwrctrlpriv.mutex_lock);
 			r8712_set_rpwm(padapter, PS_STATE_S4);
-			up(&(padapter->pwrctrlpriv.lock));
+			mutex_unlock(&padapter->pwrctrlpriv.mutex_lock);
 		}
 		pcmd_r = pcmd;
 		break;
···
 			}
 			if (pcmd->cmdcode == GEN_CMD_CODE(_SetPwrMode)) {
 				if (padapter->pwrctrlpriv.bSleep) {
-					_enter_pwrlock(&(padapter->
-						       pwrctrlpriv.lock));
+					mutex_lock(&padapter->
+						       pwrctrlpriv.mutex_lock);
 					r8712_set_rpwm(padapter, PS_STATE_S2);
-					up(&padapter->pwrctrlpriv.lock);
+					mutex_unlock(&padapter->pwrctrlpriv.mutex_lock);
 				}
 			}
 			r8712_free_cmd_obj(pcmd);

drivers/staging/rtl8712/rtl871x_pwrctrl.c

···
 	if (pwrpriv->cpwm_tog == ((preportpwrstate->state) & 0x80))
 		return;
 	del_timer(&padapter->pwrctrlpriv.rpwm_check_timer);
-	_enter_pwrlock(&pwrpriv->lock);
+	mutex_lock(&pwrpriv->mutex_lock);
 	pwrpriv->cpwm = (preportpwrstate->state) & 0xf;
 	if (pwrpriv->cpwm >= PS_STATE_S2) {
 		if (pwrpriv->alives & CMD_ALIVE)
 			complete(&(pcmdpriv->cmd_queue_comp));
 	}
 	pwrpriv->cpwm_tog = (preportpwrstate->state) & 0x80;
-	up(&pwrpriv->lock);
+	mutex_unlock(&pwrpriv->mutex_lock);
 }
 
 static inline void register_task_alive(struct pwrctrl_priv *pwrctrl, uint tag)
···
 	struct _adapter *padapter = container_of(pwrpriv,
 				    struct _adapter, pwrctrlpriv);
 	if (!pwrpriv->bSleep) {
-		_enter_pwrlock(&pwrpriv->lock);
+		mutex_lock(&pwrpriv->mutex_lock);
 		if (pwrpriv->pwr_mode == PS_MODE_ACTIVE)
 			r8712_set_rpwm(padapter, PS_STATE_S4);
-		up(&pwrpriv->lock);
+		mutex_lock(&pwrpriv->mutex_lock);
 	}
 }
 
···
 	struct _adapter *padapter = container_of(pwrpriv,
 				    struct _adapter, pwrctrlpriv);
 	if (pwrpriv->cpwm != pwrpriv->rpwm) {
-		_enter_pwrlock(&pwrpriv->lock);
+		mutex_lock(&pwrpriv->mutex_lock);
 		r8712_read8(padapter, SDIO_HCPWM);
 		pwrpriv->rpwm_retry = 1;
 		r8712_set_rpwm(padapter, pwrpriv->rpwm);
-		up(&pwrpriv->lock);
+		mutex_unlock(&pwrpriv->mutex_lock);
 	}
 }
 
···
 	struct pwrctrl_priv *pwrctrlpriv = &padapter->pwrctrlpriv;
 
 	memset((unsigned char *)pwrctrlpriv, 0, sizeof(struct pwrctrl_priv));
-	sema_init(&pwrctrlpriv->lock, 1);
+	mutex_init(&pwrctrlpriv->mutex_lock);
 	pwrctrlpriv->cpwm = PS_STATE_S4;
 	pwrctrlpriv->pwr_mode = PS_MODE_ACTIVE;
 	pwrctrlpriv->smart_ps = 0;
···
 	uint res = _SUCCESS;
 	struct pwrctrl_priv *pwrctrl = &padapter->pwrctrlpriv;
 
-	_enter_pwrlock(&pwrctrl->lock);
+	mutex_lock(&pwrctrl->mutex_lock);
 	register_task_alive(pwrctrl, CMD_ALIVE);
 	if (pwrctrl->cpwm < PS_STATE_S2) {
 		r8712_set_rpwm(padapter, PS_STATE_S3);
 		res = _FAIL;
 	}
-	up(&pwrctrl->lock);
+	mutex_unlock(&pwrctrl->mutex_lock);
 	return res;
 }
 
···
 {
 	struct pwrctrl_priv *pwrctrl = &padapter->pwrctrlpriv;
 
-	_enter_pwrlock(&pwrctrl->lock);
+	mutex_lock(&pwrctrl->mutex_lock);
 	unregister_task_alive(pwrctrl, CMD_ALIVE);
 	if ((pwrctrl->cpwm > PS_STATE_S2) &&
 	   (pwrctrl->pwr_mode > PS_MODE_ACTIVE)) {
···
 			r8712_set_rpwm(padapter, PS_STATE_S0);
 		}
 	}
-	up(&pwrctrl->lock);
+	mutex_unlock(&pwrctrl->mutex_lock);
 }

drivers/staging/rtl8712/rtl871x_pwrctrl.h

···
 	unsigned short rsvd;
 };
 
-static inline void _enter_pwrlock(struct semaphore *plock)
-{
-	_down_sema(plock);
-}
-
 struct	pwrctrl_priv {
-	struct semaphore lock;
+	struct mutex mutex_lock;
 	/*volatile*/ u8 rpwm; /* requested power state for fw */
 	/* fw current power state. updated when 1. read from HCPWM or
 	 * 2. driver lowers power level */