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From:   "Fabio M. De Francesco" <fmdefrancesco@gmail.com>
To:     Larry Finger <Larry.Finger@lwfinger.net>,
        Philip Potter <phil@philpotter.co.uk>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Pavel Skripkin <paskripkin@gmail.com>,
        linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org,
        David Laight <david.Laight@aculab.com>,
        Dan Carpenter <dan.carpenter@oracle.com>
Cc:     "Fabio M . De Francesco" <fmdefrancesco@gmail.com>
Subject: [PATCH v5 19/19] staging: r8188eu: remove shared buffer for usb requests
Date:   Wed, 15 Sep 2021 14:41:49 +0200
Message-Id: <20210915124149.27543-20-fmdefrancesco@gmail.com>
In-Reply-To: <20210915124149.27543-1-fmdefrancesco@gmail.com>
References: <20210915124149.27543-1-fmdefrancesco@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
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From: Pavel Skripkin <paskripkin@gmail.com>

This driver used shared buffer for usb requests. It led to using
mutexes, i.e no usb requests can be done in parallel.

USB requests can be fired in parallel since USB Core allows it. In
order to allow them, remove usb_vendor_req_buf from dvobj_priv (since
USB I/O is the only user of it) and remove also usb_vendor_req_mutex
(since there is nothing to protect).

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 | 29 ++++++++++-----------
 drivers/staging/r8188eu/include/drv_types.h |  5 ----
 drivers/staging/r8188eu/os_dep/usb_intf.c   | 29 +--------------------
 3 files changed, 15 insertions(+), 48 deletions(-)

diff --git a/drivers/staging/r8188eu/hal/usb_ops_linux.c b/drivers/staging/r8188eu/hal/usb_ops_linux.c
index 656f3a774e48..0ed4e6c8b1f5 100644
--- a/drivers/staging/r8188eu/hal/usb_ops_linux.c
+++ b/drivers/staging/r8188eu/hal/usb_ops_linux.c
@@ -19,9 +19,9 @@ static int usb_read(struct intf_hdl *intfhdl, u16 addr, void *data, u8 size)
 	if (adapt->bSurpriseRemoved || adapt->pwrctrlpriv.pnp_bstop_trx)
 		return -EPERM;
 
-	mutex_lock(&dvobjpriv->usb_vendor_req_mutex);
-
-	io_buf = dvobjpriv->usb_vendor_req_buf;
+	io_buf = kmalloc(size, GFP_KERNEL);
+	if (!io_buf)
+		return -ENOMEM;
 
 	status = usb_control_msg_recv(udev, 0, REALTEK_USB_VENQT_CMD_REQ,
 				      REALTEK_USB_VENQT_READ, addr,
@@ -39,7 +39,7 @@ static int usb_read(struct intf_hdl *intfhdl, u16 addr, void *data, u8 size)
 		 * exist or is not enabled.
 		 */
 		adapt->bSurpriseRemoved = true;
-		goto mutex_unlock;
+		goto end;
 	}
 
 	if (status < 0) {
@@ -49,15 +49,14 @@ static int usb_read(struct intf_hdl *intfhdl, u16 addr, void *data, u8 size)
 		if (rtw_inc_and_chk_continual_urb_error(dvobjpriv))
 			adapt->bSurpriseRemoved = true;
 
-		goto mutex_unlock;
+		goto end;
 	}
 
 	rtw_reset_continual_urb_error(dvobjpriv);
 	memcpy(data, io_buf, size);
 
-mutex_unlock:
-	mutex_unlock(&dvobjpriv->usb_vendor_req_mutex);
-
+end:
+	kfree(io_buf);
 	return status;
 }
 
@@ -72,9 +71,10 @@ static int usb_write(struct intf_hdl *intfhdl, u16 addr, void *data, u8 size)
 	if (adapt->bSurpriseRemoved || adapt->pwrctrlpriv.pnp_bstop_trx)
 		return -EPERM;
 
-	mutex_lock(&dvobjpriv->usb_vendor_req_mutex);
+	io_buf = kmalloc(size, GFP_KERNEL);
+	if (!io_buf)
+		return -ENOMEM;
 
-	io_buf = dvobjpriv->usb_vendor_req_buf;
 	memcpy(io_buf, data, size);
 
 	status = usb_control_msg_send(udev, 0, REALTEK_USB_VENQT_CMD_REQ,
@@ -93,7 +93,7 @@ static int usb_write(struct intf_hdl *intfhdl, u16 addr, void *data, u8 size)
 		 * exist or is not enabled.
 		 */
 		adapt->bSurpriseRemoved = true;
-		goto mutex_unlock;
+		goto end;
 	}
 
 	if (status < 0) {
@@ -103,14 +103,13 @@ static int usb_write(struct intf_hdl *intfhdl, u16 addr, void *data, u8 size)
 		if (rtw_inc_and_chk_continual_urb_error(dvobjpriv))
 			adapt->bSurpriseRemoved = true;
 
-		goto mutex_unlock;
+		goto end;
 	}
 
 	rtw_reset_continual_urb_error(dvobjpriv);
 
-mutex_unlock:
-	mutex_unlock(&dvobjpriv->usb_vendor_req_mutex);
-
+end:
+	kfree(io_buf);
 	return status;
 }
 
diff --git a/drivers/staging/r8188eu/include/drv_types.h b/drivers/staging/r8188eu/include/drv_types.h
index 626c6273be6f..499b2bce8cbe 100644
--- a/drivers/staging/r8188eu/include/drv_types.h
+++ b/drivers/staging/r8188eu/include/drv_types.h
@@ -168,11 +168,6 @@ struct dvobj_priv {
 	int	ep_num[5]; /* endpoint number */
 	int	RegUsbSS;
 	struct semaphore usb_suspend_sema;
-	struct mutex  usb_vendor_req_mutex;
-
-	u8 *usb_alloc_vendor_req_buf;
-	u8 *usb_vendor_req_buf;
-
 	struct usb_interface *pusbintf;
 	struct usb_device *pusbdev;
 
diff --git a/drivers/staging/r8188eu/os_dep/usb_intf.c b/drivers/staging/r8188eu/os_dep/usb_intf.c
index 306325818a9a..7603cb026368 100644
--- a/drivers/staging/r8188eu/os_dep/usb_intf.c
+++ b/drivers/staging/r8188eu/os_dep/usb_intf.c
@@ -73,29 +73,6 @@ 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)
-{
-	u8 rst = _SUCCESS;
-
-	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) {
-		DBG_88E("alloc usb_vendor_req_buf failed... /n");
-		rst = _FAIL;
-		goto exit;
-	}
-	dvobj->usb_vendor_req_buf = (u8 *)N_BYTE_ALIGMENT((size_t)(dvobj->usb_alloc_vendor_req_buf), ALIGNMENT_UNIT);
-exit:
-	return rst;
-}
-
-static void rtw_deinit_intf_priv(struct dvobj_priv *dvobj)
-{
-	kfree(dvobj->usb_alloc_vendor_req_buf);
-	mutex_destroy(&dvobj->usb_vendor_req_mutex);
-}
-
 static struct dvobj_priv *usb_dvobj_init(struct usb_interface *usb_intf)
 {
 	int	i;
@@ -158,9 +135,6 @@ 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);
@@ -169,7 +143,6 @@ static struct dvobj_priv *usb_dvobj_init(struct usb_interface *usb_intf)
 
 	status = _SUCCESS;
 
-free_dvobj:
 	if (status != _SUCCESS && pdvobjpriv) {
 		usb_set_intfdata(usb_intf, NULL);
 		kfree(pdvobjpriv);
@@ -200,7 +173,7 @@ 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