From 7e4c7947b42c4d9af0daa8d51dc58d4f17605dd9 Mon Sep 17 00:00:00 2001 From: "Fabio M. De Francesco" Date: Fri, 22 Oct 2021 19:19:17 +0200 Subject: [PATCH] staging: r8188eu: Use a Mutex instead of a binary Semaphore Use a Mutex instead of a binary Semaphore for the purpose of enforcing mutual exclusive access to the "pwrctrl_priv" structure. Mutexes are sleeping locks similar to Semaphores with a 'count' of one (like binary Semaphores), however they have a simpler interface, more efficient performance, and additional constraints. There is no change in the logic of the new code; however it is more simple because it gets rid of four unnecessary wrappers: _init_pwrlock(), _enter_pwrlock(),_exit_pwrlock(), _rtw_down_sema(). Actually, there is a change in the state in which the code waits for acquiring locks, because it makes it in an uninterruptible state (instead the old code used down_interruptibe()). Interruptible waits are neither required nor wanted in this driver. Tested with ASUSTek Computer, Inc. Realtek 8188EUS [USB-N10 Nano]. Acked-by: Larry Finger Signed-off-by: Fabio M. De Francesco Link: https://lore.kernel.org/r/20211022171917.24363-1-fmdefrancesco@gmail.com Signed-off-by: Greg Kroah-Hartman --- drivers/staging/r8188eu/core/rtw_pwrctrl.c | 10 +++++----- drivers/staging/r8188eu/include/osdep_service.h | 2 -- drivers/staging/r8188eu/include/rtw_pwrctrl.h | 17 +---------------- drivers/staging/r8188eu/os_dep/osdep_service.c | 8 -------- drivers/staging/r8188eu/os_dep/usb_intf.c | 8 ++++---- 5 files changed, 10 insertions(+), 35 deletions(-) diff --git a/drivers/staging/r8188eu/core/rtw_pwrctrl.c b/drivers/staging/r8188eu/core/rtw_pwrctrl.c index 19cac58..5d595cf 100644 --- a/drivers/staging/r8188eu/core/rtw_pwrctrl.c +++ b/drivers/staging/r8188eu/core/rtw_pwrctrl.c @@ -21,7 +21,7 @@ void ips_enter(struct adapter *padapter) return; } - _enter_pwrlock(&pwrpriv->lock); + mutex_lock(&pwrpriv->lock); pwrpriv->bips_processing = true; @@ -42,7 +42,7 @@ void ips_enter(struct adapter *padapter) } pwrpriv->bips_processing = false; - _exit_pwrlock(&pwrpriv->lock); + mutex_unlock(&pwrpriv->lock); } int ips_leave(struct adapter *padapter) @@ -53,7 +53,7 @@ int ips_leave(struct adapter *padapter) int result = _SUCCESS; int keyid; - _enter_pwrlock(&pwrpriv->lock); + mutex_lock(&pwrpriv->lock); if ((pwrpriv->rf_pwrstate == rf_off) && (!pwrpriv->bips_processing)) { pwrpriv->bips_processing = true; @@ -87,7 +87,7 @@ int ips_leave(struct adapter *padapter) pwrpriv->bpower_saving = false; } - _exit_pwrlock(&pwrpriv->lock); + mutex_unlock(&pwrpriv->lock); return result; } @@ -337,7 +337,7 @@ void rtw_init_pwrctrl_priv(struct adapter *padapter) { struct pwrctrl_priv *pwrctrlpriv = &padapter->pwrctrlpriv; - _init_pwrlock(&pwrctrlpriv->lock); + mutex_init(&pwrctrlpriv->lock); pwrctrlpriv->rf_pwrstate = rf_on; pwrctrlpriv->ips_enter_cnts = 0; pwrctrlpriv->ips_leave_cnts = 0; diff --git a/drivers/staging/r8188eu/include/osdep_service.h b/drivers/staging/r8188eu/include/osdep_service.h index 886a1b6..efab3a9 100644 --- a/drivers/staging/r8188eu/include/osdep_service.h +++ b/drivers/staging/r8188eu/include/osdep_service.h @@ -141,8 +141,6 @@ extern unsigned char RSN_TKIP_CIPHER[4]; void *rtw_malloc2d(int h, int w, int size); -u32 _rtw_down_sema(struct semaphore *sema); - #define rtw_init_queue(q) \ do { \ INIT_LIST_HEAD(&((q)->queue)); \ diff --git a/drivers/staging/r8188eu/include/rtw_pwrctrl.h b/drivers/staging/r8188eu/include/rtw_pwrctrl.h index 04236e42..b19ef79 100644 --- a/drivers/staging/r8188eu/include/rtw_pwrctrl.h +++ b/drivers/staging/r8188eu/include/rtw_pwrctrl.h @@ -27,21 +27,6 @@ enum power_mgnt { PS_MODE_NUM }; -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 */ /* RF state. */ @@ -60,7 +45,7 @@ enum { /* for ips_mode */ }; struct pwrctrl_priv { - struct semaphore lock; + struct mutex lock; /* Mutex used to protect struct pwrctrl_priv */ u8 pwr_mode; u8 smart_ps; diff --git a/drivers/staging/r8188eu/os_dep/osdep_service.c b/drivers/staging/r8188eu/os_dep/osdep_service.c index 6bee194..59bdd0a 100644 --- a/drivers/staging/r8188eu/os_dep/osdep_service.c +++ b/drivers/staging/r8188eu/os_dep/osdep_service.c @@ -42,14 +42,6 @@ Otherwise, there will be racing condition. Caller must check if the list is empty before calling rtw_list_delete */ -u32 _rtw_down_sema(struct semaphore *sema) -{ - if (down_interruptible(sema)) - return _FAIL; - else - return _SUCCESS; -} - inline u32 rtw_systime_to_ms(u32 systime) { return systime * 1000 / HZ; diff --git a/drivers/staging/r8188eu/os_dep/usb_intf.c b/drivers/staging/r8188eu/os_dep/usb_intf.c index 40f2481a..6b93830 100644 --- a/drivers/staging/r8188eu/os_dep/usb_intf.c +++ b/drivers/staging/r8188eu/os_dep/usb_intf.c @@ -234,7 +234,7 @@ 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->lock); /* s1. */ if (pnetdev) { netif_carrier_off(pnetdev); @@ -263,7 +263,7 @@ 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->lock); if (check_fwstate(pmlmepriv, _FW_UNDER_SURVEY)) rtw_indicate_scan_done(padapter, 1); @@ -292,7 +292,7 @@ static int rtw_resume(struct usb_interface *pusb_intf) pnetdev = padapter->pnetdev; pwrpriv = &padapter->pwrctrlpriv; - _enter_pwrlock(&pwrpriv->lock); + mutex_lock(&pwrpriv->lock); rtw_reset_drv_sw(padapter); if (pwrpriv) pwrpriv->bkeepfwalive = false; @@ -304,7 +304,7 @@ static int rtw_resume(struct usb_interface *pusb_intf) netif_device_attach(pnetdev); netif_carrier_on(pnetdev); - _exit_pwrlock(&pwrpriv->lock); + mutex_unlock(&pwrpriv->lock); if (padapter->pid[1] != 0) { DBG_88E("pid[1]:%d\n", padapter->pid[1]); -- 2.7.4