leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

staging: r8188eu: Use a Mutex instead of a binary Semaphore

Browse Source 
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 <Larry.Finger@lwfinger.net>
Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Link: https://lore.kernel.org/r/20211022171917.24363-1-fmdefrancesco@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Fabio M. De Francesco 2021-10-22 19:19:17 +02:00 committed by Greg Kroah-Hartman
parent 75c5e966bd
commit 7e4c7947b4
5 changed files with 10 additions and 35 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
drivers/staging/r8188eu/core/rtw_pwrctrl.c
View File

@ -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;

2
drivers/staging/r8188eu/include/osdep_service.h
View File

@ -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)); \

17
drivers/staging/r8188eu/include/rtw_pwrctrl.h
View File

@ -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;

8
drivers/staging/r8188eu/os_dep/osdep_service.c
View File

@ -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;

8
drivers/staging/r8188eu/os_dep/usb_intf.c
View File

@ -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]);