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Subject[PATCH v2] staging: r8188eu: remove _rtw_mutex_{init,free}
Date
While testing Fabio's patch I hit lockdep warning about possible
deadlock:

[ 252.063305] WARNING: possible recursive locking detected
[ 252.063642] 5.14.0+ #9 Tainted: G C
[ 252.063946] --------------------------------------------
[ 252.064282] ip/335 is trying to acquire lock:
[ 252.064560] ffff888009ebad28 (pmutex){+.+.}-{4:4}, at: usbctrl_vendorreq+0xc5/0x4a0 [r8188eu]
[ 252.065168]
[ 252.065168] but task is already holding lock:
[ 252.065536] ffffffffc021b3b8 (pmutex){+.+.}-{4:4}, at: netdev_open+0x3a/0x5f [r8188eu]
[ 252.066085]
[ 252.066085] other info that might help us debug this:
[ 252.066494] Possible unsafe locking scenario:
[ 252.066494]
[ 252.066866] CPU0
[ 252.067025] ----
[ 252.067184] lock(pmutex);
[ 252.067367] lock(pmutex);

There is one problem with this warning: there is no pmutex in this
driver, *BUT* all mutexes are initialized via private _rtw_mutex_init
API, which had struct mutex *pmutex argument.

So, all mutexes in this driver had same name in lockdep map. Of course,
lockdep will complain about any nested locking.

Fix it by open-coding _rtw_mutex_{init,free} wrappers, because we do not
need them at all.

Cc: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
---

Changes in v2:
Removed Fixes tag (suggested by Greg)

---
drivers/staging/r8188eu/core/rtw_sreset.c | 2 +-
drivers/staging/r8188eu/core/rtw_xmit.c | 4 ++--
drivers/staging/r8188eu/include/osdep_service.h | 2 --
drivers/staging/r8188eu/os_dep/osdep_service.c | 10 ----------
drivers/staging/r8188eu/os_dep/usb_intf.c | 8 ++++----
5 files changed, 7 insertions(+), 19 deletions(-)

diff --git a/drivers/staging/r8188eu/core/rtw_sreset.c b/drivers/staging/r8188eu/core/rtw_sreset.c
index c831033d20a9..1787c2d7ea5f 100644
--- a/drivers/staging/r8188eu/core/rtw_sreset.c
+++ b/drivers/staging/r8188eu/core/rtw_sreset.c
@@ -8,7 +8,7 @@ void sreset_init_value(struct adapter *padapter)
struct hal_data_8188e *pHalData = GET_HAL_DATA(padapter);
struct sreset_priv *psrtpriv = &pHalData->srestpriv;

- _rtw_mutex_init(&psrtpriv->silentreset_mutex);
+ mutex_init(&psrtpriv->silentreset_mutex);
psrtpriv->silent_reset_inprogress = false;
psrtpriv->wifi_error_status = WIFI_STATUS_SUCCESS;
psrtpriv->last_tx_time = 0;
diff --git a/drivers/staging/r8188eu/core/rtw_xmit.c b/drivers/staging/r8188eu/core/rtw_xmit.c
index 46fe62c7c32c..bbb9889c4b89 100644
--- a/drivers/staging/r8188eu/core/rtw_xmit.c
+++ b/drivers/staging/r8188eu/core/rtw_xmit.c
@@ -196,7 +196,7 @@ s32 _rtw_init_xmit_priv(struct xmit_priv *pxmitpriv, struct adapter *padapter)
pxmitpriv->voq_cnt = 0;

pxmitpriv->ack_tx = false;
- _rtw_mutex_init(&pxmitpriv->ack_tx_mutex);
+ mutex_init(&pxmitpriv->ack_tx_mutex);
rtw_sctx_init(&pxmitpriv->ack_tx_ops, 0);

rtw_hal_init_xmit_priv(padapter);
@@ -243,7 +243,7 @@ void _rtw_free_xmit_priv(struct xmit_priv *pxmitpriv)

rtw_free_hwxmits(padapter);

- _rtw_mutex_free(&pxmitpriv->ack_tx_mutex);
+ mutex_destroy(&pxmitpriv->ack_tx_mutex);
}

static void update_attrib_vcs_info(struct adapter *padapter, struct xmit_frame *pxmitframe)
diff --git a/drivers/staging/r8188eu/include/osdep_service.h b/drivers/staging/r8188eu/include/osdep_service.h
index 029aa4e92c9b..05bac61c3a19 100644
--- a/drivers/staging/r8188eu/include/osdep_service.h
+++ b/drivers/staging/r8188eu/include/osdep_service.h
@@ -155,8 +155,6 @@ extern unsigned char RSN_TKIP_CIPHER[4];
void *rtw_malloc2d(int h, int w, int size);

u32 _rtw_down_sema(struct semaphore *sema);
-void _rtw_mutex_init(struct mutex *pmutex);
-void _rtw_mutex_free(struct mutex *pmutex);

void _rtw_init_queue(struct __queue *pqueue);

diff --git a/drivers/staging/r8188eu/os_dep/osdep_service.c b/drivers/staging/r8188eu/os_dep/osdep_service.c
index 95ac6086370b..4328992907f2 100644
--- a/drivers/staging/r8188eu/os_dep/osdep_service.c
+++ b/drivers/staging/r8188eu/os_dep/osdep_service.c
@@ -67,16 +67,6 @@ u32 _rtw_down_sema(struct semaphore *sema)
return _SUCCESS;
}

-void _rtw_mutex_init(struct mutex *pmutex)
-{
- mutex_init(pmutex);
-}
-
-void _rtw_mutex_free(struct mutex *pmutex)
-{
- mutex_destroy(pmutex);
-}
-
void _rtw_init_queue(struct __queue *pqueue)
{
INIT_LIST_HEAD(&pqueue->queue);
diff --git a/drivers/staging/r8188eu/os_dep/usb_intf.c b/drivers/staging/r8188eu/os_dep/usb_intf.c
index bb85ab77fd26..8a981a30ea1f 100644
--- a/drivers/staging/r8188eu/os_dep/usb_intf.c
+++ b/drivers/staging/r8188eu/os_dep/usb_intf.c
@@ -116,7 +116,7 @@ static u8 rtw_init_intf_priv(struct dvobj_priv *dvobj)
{
u8 rst = _SUCCESS;

- _rtw_mutex_init(&dvobj->usb_vendor_req_mutex);
+ mutex_init(&dvobj->usb_vendor_req_mutex);

dvobj->usb_alloc_vendor_req_buf = kzalloc(MAX_USB_IO_CTL_SIZE, GFP_KERNEL);
if (!dvobj->usb_alloc_vendor_req_buf) {
@@ -132,7 +132,7 @@ static u8 rtw_init_intf_priv(struct dvobj_priv *dvobj)
static void rtw_deinit_intf_priv(struct dvobj_priv *dvobj)
{
kfree(dvobj->usb_alloc_vendor_req_buf);
- _rtw_mutex_free(&dvobj->usb_vendor_req_mutex);
+ mutex_destroy(&dvobj->usb_vendor_req_mutex);
}

static struct dvobj_priv *usb_dvobj_init(struct usb_interface *usb_intf)
@@ -760,7 +760,7 @@ static int __init rtw_drv_entry(void)
{
DBG_88E(DRV_NAME " driver version=%s\n", DRIVERVERSION);

- _rtw_mutex_init(&usb_drv->hw_init_mutex);
+ mutex_init(&usb_drv->hw_init_mutex);

usb_drv->drv_registered = true;
return usb_register(&usb_drv->usbdrv);
@@ -773,7 +773,7 @@ static void __exit rtw_drv_halt(void)
usb_drv->drv_registered = false;
usb_deregister(&usb_drv->usbdrv);

- _rtw_mutex_free(&usb_drv->hw_init_mutex);
+ mutex_destroy(&usb_drv->hw_init_mutex);
DBG_88E("-rtw_drv_halt\n");
}

--
2.33.0
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