[PATCH v3 3/4] staging: r8188eu: pwrctrl_priv: Replace semaphore 'lock' with mutex

[Binoy Jayan <binoy.jayan@linaro.org>]

The semaphore 'lock' in pwrctrl_priv is 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.
Also, remove the now unused wrappers _init_pwrlock, _enter_pwrlock,
_exit_pwrlock and _rtw_down_sema.

Signed-off-by: Binoy Jayan <binoy.jayan@linaro.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Larry Finger <Larry.Finger@lwfinger.net>
---
 drivers/staging/rtl8188eu/core/rtw_pwrctrl.c      | 20 ++++++++++----------
 drivers/staging/rtl8188eu/include/osdep_service.h |  3 +--
 drivers/staging/rtl8188eu/include/rtw_event.h     |  1 +
 drivers/staging/rtl8188eu/include/rtw_pwrctrl.h   | 17 +----------------
 drivers/staging/rtl8188eu/os_dep/osdep_service.c  |  7 -------
 drivers/staging/rtl8188eu/os_dep/usb_intf.c       |  8 ++++----
 6 files changed, 17 insertions(+), 39 deletions(-)

diff --git a/drivers/staging/rtl8188eu/core/rtw_pwrctrl.c b/drivers/staging/rtl8188eu/core/rtw_pwrctrl.c
index 59c6d8a..0b70fe7 100644
--- a/drivers/staging/rtl8188eu/core/rtw_pwrctrl.c
+++ b/drivers/staging/rtl8188eu/core/rtw_pwrctrl.c
@@ -38,7 +38,7 @@ static int rtw_hw_suspend(struct adapter *padapter)
 	LeaveAllPowerSaveMode(padapter);
 
 	DBG_88E("==> rtw_hw_suspend\n");
-	_enter_pwrlock(&pwrpriv->lock);
+	mutex_lock(&pwrpriv->mutex_lock);
 	pwrpriv->bips_processing = true;
 	/* s1. */
 	if (pnetdev) {
@@ -73,7 +73,7 @@ static int rtw_hw_suspend(struct adapter *padapter)
 	pwrpriv->rf_pwrstate = rf_off;
 	pwrpriv->bips_processing = false;
 
-	_exit_pwrlock(&pwrpriv->lock);
+	mutex_unlock(&pwrpriv->mutex_lock);
 
 	return 0;
 
@@ -90,12 +90,12 @@ static int rtw_hw_resume(struct adapter *padapter)
 
 	/* system resume */
 	DBG_88E("==> rtw_hw_resume\n");
-	_enter_pwrlock(&pwrpriv->lock);
+	mutex_lock(&pwrpriv->mutex_lock);
 	pwrpriv->bips_processing = true;
 	rtw_reset_drv_sw(padapter);
 
 	if (pm_netdev_open(pnetdev, false) != 0) {
-		_exit_pwrlock(&pwrpriv->lock);
+		mutex_unlock(&pwrpriv->mutex_lock);
 		goto error_exit;
 	}
 
@@ -113,7 +113,7 @@ static int rtw_hw_resume(struct adapter *padapter)
 	pwrpriv->rf_pwrstate = rf_on;
 	pwrpriv->bips_processing = false;
 
-	_exit_pwrlock(&pwrpriv->lock);
+	mutex_unlock(&pwrpriv->mutex_lock);
 
 
 	return 0;
@@ -138,7 +138,7 @@ void ips_enter(struct adapter *padapter)
 		return;
 	}
 
-	_enter_pwrlock(&pwrpriv->lock);
+	mutex_lock(&pwrpriv->mutex_lock);
 
 	pwrpriv->bips_processing = true;
 
@@ -159,7 +159,7 @@ void ips_enter(struct adapter *padapter)
 	}
 	pwrpriv->bips_processing = false;
 
-	_exit_pwrlock(&pwrpriv->lock);
+	mutex_unlock(&pwrpriv->mutex_lock);
 }
 
 int ips_leave(struct adapter *padapter)
@@ -171,7 +171,7 @@ int ips_leave(struct adapter *padapter)
 	int keyid;
 
 
-	_enter_pwrlock(&pwrpriv->lock);
+	mutex_lock(&pwrpriv->mutex_lock);
 
 	if ((pwrpriv->rf_pwrstate == rf_off) && (!pwrpriv->bips_processing)) {
 		pwrpriv->bips_processing = true;
@@ -205,7 +205,7 @@ int ips_leave(struct adapter *padapter)
 		pwrpriv->bpower_saving = false;
 	}
 
-	_exit_pwrlock(&pwrpriv->lock);
+	mutex_unlock(&pwrpriv->mutex_lock);
 
 	return result;
 }
@@ -504,7 +504,7 @@ void rtw_init_pwrctrl_priv(struct adapter *padapter)
 {
 	struct pwrctrl_priv *pwrctrlpriv = &padapter->pwrctrlpriv;
 
-	_init_pwrlock(&pwrctrlpriv->lock);
+	mutex_init(&pwrctrlpriv->mutex_lock);
 	pwrctrlpriv->rf_pwrstate = rf_on;
 	pwrctrlpriv->ips_enter_cnts = 0;
 	pwrctrlpriv->ips_leave_cnts = 0;
diff --git a/drivers/staging/rtl8188eu/include/osdep_service.h b/drivers/staging/rtl8188eu/include/osdep_service.h
index 5475956..c53c9ea 100644
--- a/drivers/staging/rtl8188eu/include/osdep_service.h
+++ b/drivers/staging/rtl8188eu/include/osdep_service.h
@@ -36,6 +36,7 @@
 #include <linux/atomic.h>
 #include <linux/io.h>
 #include <linux/semaphore.h>
+#include <linux/mutex.h>
 #include <linux/sem.h>
 #include <linux/sched.h>
 #include <linux/etherdevice.h>
@@ -78,8 +79,6 @@ u8 *_rtw_malloc(u32 sz);
 
 void *rtw_malloc2d(int h, int w, int size);
 
-u32  _rtw_down_sema(struct semaphore *sema);
-
 void _rtw_init_queue(struct __queue *pqueue);
 
 struct rtw_netdev_priv_indicator {
diff --git a/drivers/staging/rtl8188eu/include/rtw_event.h b/drivers/staging/rtl8188eu/include/rtw_event.h
index 5c34e56..0dc63f2 100644
--- a/drivers/staging/rtl8188eu/include/rtw_event.h
+++ b/drivers/staging/rtl8188eu/include/rtw_event.h
@@ -19,6 +19,7 @@
 
 #include <wlan_bssdef.h>
 #include <linux/semaphore.h>
+#include <linux/mutex.h>
 #include <linux/sem.h>
 
 /*
diff --git a/drivers/staging/rtl8188eu/include/rtw_pwrctrl.h b/drivers/staging/rtl8188eu/include/rtw_pwrctrl.h
index 9680e2e..18a9e74 100644
--- a/drivers/staging/rtl8188eu/include/rtw_pwrctrl.h
+++ b/drivers/staging/rtl8188eu/include/rtw_pwrctrl.h
@@ -92,21 +92,6 @@ struct reportpwrstate_parm {
 	unsigned short rsvd;
 };
 
-static inline void _init_pwrlock(struct semaphore  *plock)
-{
-	sema_init(plock, 1);
-}
-
-static inline void _enter_pwrlock(struct semaphore  *plock)
-{
-	_rtw_down_sema(plock);
-}
-
-static inline void _exit_pwrlock(struct semaphore  *plock)
-{
-	up(plock);
-}
-
 #define LPS_DELAY_TIME	1*HZ /*  1 sec */
 
 #define EXE_PWR_NONE	0x01
@@ -157,7 +142,7 @@ enum { /*  for ips_mode */
 };
 
 struct pwrctrl_priv {
-	struct semaphore lock;
+	struct mutex mutex_lock;
 	volatile u8 rpwm; /*  requested power state for fw */
 	volatile u8 cpwm; /*  fw current power state. updated when
 			   * 1. read from HCPWM 2. driver lowers power level */
diff --git a/drivers/staging/rtl8188eu/os_dep/osdep_service.c b/drivers/staging/rtl8188eu/os_dep/osdep_service.c
index 764250b..24d1774 100644
--- a/drivers/staging/rtl8188eu/os_dep/osdep_service.c
+++ b/drivers/staging/rtl8188eu/os_dep/osdep_service.c
@@ -55,13 +55,6 @@ void *rtw_malloc2d(int h, int w, int size)
 	return a;
 }
 
-u32 _rtw_down_sema(struct semaphore *sema)
-{
-	if (down_interruptible(sema))
-		return _FAIL;
-	return _SUCCESS;
-}
-
 void	_rtw_init_queue(struct __queue *pqueue)
 {
 	INIT_LIST_HEAD(&(pqueue->queue));
diff --git a/drivers/staging/rtl8188eu/os_dep/usb_intf.c b/drivers/staging/rtl8188eu/os_dep/usb_intf.c
index 11d51a3..a5ba1e4 100644
--- a/drivers/staging/rtl8188eu/os_dep/usb_intf.c
+++ b/drivers/staging/rtl8188eu/os_dep/usb_intf.c
@@ -238,7 +238,7 @@ static int rtw_suspend(struct usb_interface *pusb_intf, pm_message_t message)
 	rtw_cancel_all_timer(padapter);
 	LeaveAllPowerSaveMode(padapter);
 
-	_enter_pwrlock(&pwrpriv->lock);
+	mutex_lock(&pwrpriv->mutex_lock);
 	/* s1. */
 	if (pnetdev) {
 		netif_carrier_off(pnetdev);
@@ -267,7 +267,7 @@ static int rtw_suspend(struct usb_interface *pusb_intf, pm_message_t message)
 	rtw_free_network_queue(padapter, true);
 
 	rtw_dev_unload(padapter);
-	_exit_pwrlock(&pwrpriv->lock);
+	mutex_unlock(&pwrpriv->mutex_lock);
 
 	if (check_fwstate(pmlmepriv, _FW_UNDER_SURVEY))
 		rtw_indicate_scan_done(padapter, 1);
@@ -298,7 +298,7 @@ static int rtw_resume_process(struct adapter *padapter)
 		goto exit;
 	}
 
-	_enter_pwrlock(&pwrpriv->lock);
+	mutex_lock(&pwrpriv->mutex_lock);
 	rtw_reset_drv_sw(padapter);
 	pwrpriv->bkeepfwalive = false;
 
@@ -309,7 +309,7 @@ static int rtw_resume_process(struct adapter *padapter)
 	netif_device_attach(pnetdev);
 	netif_carrier_on(pnetdev);
 
-	_exit_pwrlock(&pwrpriv->lock);
+	mutex_unlock(&pwrpriv->mutex_lock);
 
 	rtw_roaming(padapter, NULL);
 
-- 
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