[PATCH v9 16/16] staging: r8188eu: remove usb_vendor_req_mutex

["Fabio M. De Francesco" <fmdefrancesco@gmail.com>]

From: Pavel Skripkin <paskripkin@gmail.com>

This mutex was used to protect shared buffer for USB requests. Since
buffer was removed in previous patch we can remove this mutex as well.

Furthermore, because it was used to serialize the calls to the Core USB 
API, we thoroughly tested the enabling of concurrent firing of USB requests
without the mutex and found no problems of any kind in common use cases.

Co-developed-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
---
 drivers/staging/r8188eu/hal/usb_ops_linux.c | 30 ++++++---------------
 drivers/staging/r8188eu/os_dep/usb_intf.c   | 22 ++-------------
 2 files changed, 10 insertions(+), 42 deletions(-)

diff --git a/drivers/staging/r8188eu/hal/usb_ops_linux.c b/drivers/staging/r8188eu/hal/usb_ops_linux.c
index 3ede93cd68d6..c15a75513c8c 100644
--- a/drivers/staging/r8188eu/hal/usb_ops_linux.c
+++ b/drivers/staging/r8188eu/hal/usb_ops_linux.c
@@ -16,12 +16,8 @@ static int usb_read(struct intf_hdl *intf, u16 value, void *data, u8 size)
 	int status;
 	u8 io_buf[4];
 
-	mutex_lock(&dvobjpriv->usb_vendor_req_mutex);
-
-	if (adapt->bSurpriseRemoved || adapt->pwrctrlpriv.pnp_bstop_trx) {
-		status = -EPERM;
-		goto mutex_unlock;
-	}
+	if (adapt->bSurpriseRemoved || adapt->pwrctrlpriv.pnp_bstop_trx)
+		return -EPERM;
 
 	status = usb_control_msg_recv(udev, 0, REALTEK_USB_VENQT_CMD_REQ,
 				      REALTEK_USB_VENQT_READ, value,
@@ -39,7 +35,7 @@ static int usb_read(struct intf_hdl *intf, u16 value, void *data, u8 size)
 		 * exist or is not enabled.
 		 */
 		adapt->bSurpriseRemoved = true;
-		goto mutex_unlock;
+		return status;
 	}
 
 	if (status < 0) {
@@ -49,15 +45,12 @@ static int usb_read(struct intf_hdl *intf, u16 value, void *data, u8 size)
 		if (rtw_inc_and_chk_continual_urb_error(dvobjpriv))
 			adapt->bSurpriseRemoved = true;
 
-		goto mutex_unlock;
+		return status;
 	}
 
 	rtw_reset_continual_urb_error(dvobjpriv);
 	memcpy(data, io_buf, size);
 
-mutex_unlock:
-	mutex_unlock(&dvobjpriv->usb_vendor_req_mutex);
-
 	return status;
 }
 
@@ -69,12 +62,8 @@ static int usb_write(struct intf_hdl *intf, u16 value, void *data, u8 size)
 	int status;
 	u8 io_buf[VENDOR_CMD_MAX_DATA_LEN];
 
-	mutex_lock(&dvobjpriv->usb_vendor_req_mutex);
-
-	if (adapt->bSurpriseRemoved || adapt->pwrctrlpriv.pnp_bstop_trx) {
-		status = -EPERM;
-		goto mutex_unlock;
-	}
+	if (adapt->bSurpriseRemoved || adapt->pwrctrlpriv.pnp_bstop_trx)
+		return -EPERM;
 
 	memcpy(io_buf, data, size);
 	status = usb_control_msg_send(udev, 0, REALTEK_USB_VENQT_CMD_REQ,
@@ -93,7 +82,7 @@ static int usb_write(struct intf_hdl *intf, u16 value, void *data, u8 size)
 		 * exist or is not enabled.
 		 */
 		adapt->bSurpriseRemoved = true;
-		goto mutex_unlock;
+		return status;
 	}
 
 	if (status < 0) {
@@ -103,14 +92,11 @@ static int usb_write(struct intf_hdl *intf, u16 value, void *data, u8 size)
 		if (rtw_inc_and_chk_continual_urb_error(dvobjpriv))
 			adapt->bSurpriseRemoved = true;
 
-		goto mutex_unlock;
+		return status;
 	}
 
 	rtw_reset_continual_urb_error(dvobjpriv);
 
-mutex_unlock:
-	mutex_unlock(&dvobjpriv->usb_vendor_req_mutex);
-
 	return status;
 }
 
diff --git a/drivers/staging/r8188eu/os_dep/usb_intf.c b/drivers/staging/r8188eu/os_dep/usb_intf.c
index 5ab42d55207f..2e6e6070c304 100644
--- a/drivers/staging/r8188eu/os_dep/usb_intf.c
+++ b/drivers/staging/r8188eu/os_dep/usb_intf.c
@@ -73,21 +73,9 @@ static struct rtw_usb_drv rtl8188e_usb_drv = {
 
 static struct rtw_usb_drv *usb_drv = &rtl8188e_usb_drv;
 
-static u8 rtw_init_intf_priv(struct dvobj_priv *dvobj)
-{
-	mutex_init(&dvobj->usb_vendor_req_mutex);
-	return _SUCCESS;
-}
-
-static void rtw_deinit_intf_priv(struct dvobj_priv *dvobj)
-{
-	mutex_destroy(&dvobj->usb_vendor_req_mutex);
-}
-
 static struct dvobj_priv *usb_dvobj_init(struct usb_interface *usb_intf)
 {
 	int	i;
-	int	status = _FAIL;
 	struct dvobj_priv *pdvobjpriv;
 	struct usb_host_config		*phost_conf;
 	struct usb_config_descriptor	*pconf_desc;
@@ -146,19 +134,13 @@ static struct dvobj_priv *usb_dvobj_init(struct usb_interface *usb_intf)
 		DBG_88E("NON USB_SPEED_HIGH\n");
 	}
 
-	if (rtw_init_intf_priv(pdvobjpriv) == _FAIL)
-		goto free_dvobj;
-
 	/* 3 misc */
 	sema_init(&pdvobjpriv->usb_suspend_sema, 0);
 	rtw_reset_continual_urb_error(pdvobjpriv);
 
 	usb_get_dev(pusbd);
 
-	status = _SUCCESS;
-
-free_dvobj:
-	if (status != _SUCCESS && pdvobjpriv) {
+	if (pdvobjpriv) {
 		usb_set_intfdata(usb_intf, NULL);
 		kfree(pdvobjpriv);
 		pdvobjpriv = NULL;
@@ -188,7 +170,7 @@ static void usb_dvobj_deinit(struct usb_interface *usb_intf)
 				usb_reset_device(interface_to_usbdev(usb_intf));
 			}
 		}
-		rtw_deinit_intf_priv(dvobj);
+
 		kfree(dvobj);
 	}
 
-- 
2.33.0