[PATCH v4 17/18] staging: r8188eu: Shorten calls chain of rtw_read8/16/32()

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

Shorten the calls chain of rtw_read8/16/32() down to the actual reads.
For this purpose unify the three usb_read8/16/32 into the new
usb_read(); make the latter parameterizable with 'size'; embed most of
the code of usbctrl_vendorreq() into usb_read() and use in it the new
usb_control_msg_recv() API of USB Core.

Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Co-developed-by: Pavel Skripkin <paskripkin@gmail.com>
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
---

v3->v4: 
	Make some changes according to a first review of Greg
	Kroah-Hartman; remove unnecessary while loop and a couple of
	'if' test; handle the errors returned by usb_control_msg_recv()
v2->v3: 
	No changes.
v1->v2: 
	No changes.

 drivers/staging/r8188eu/hal/usb_ops_linux.c | 56 +++++++++++++++++++--
 1 file changed, 53 insertions(+), 3 deletions(-)

diff --git a/drivers/staging/r8188eu/hal/usb_ops_linux.c b/drivers/staging/r8188eu/hal/usb_ops_linux.c
index 04402bab805e..75475b0083db 100644
--- a/drivers/staging/r8188eu/hal/usb_ops_linux.c
+++ b/drivers/staging/r8188eu/hal/usb_ops_linux.c
@@ -89,6 +89,56 @@ static int usbctrl_vendorreq(struct intf_hdl *intfhdl, u16 value, void *data, u1
 	return status;
 }
 
+static int usb_read(struct intf_hdl *intfhdl, u16 addr, void *data, u8 size)
+{
+	int status;
+	u8 *io_buf; /* pointer to I/O buffer */
+	struct adapter *adapt = intfhdl->padapter;
+	struct dvobj_priv *dvobjpriv = adapter_to_dvobj(adapt);
+	struct usb_device *udev = dvobjpriv->pusbdev;
+
+	if (adapt->bSurpriseRemoved || adapt->pwrctrlpriv.pnp_bstop_trx) {
+		status = -EPERM;
+		goto exit;
+	}
+
+	mutex_lock(&dvobjpriv->usb_vendor_req_mutex);
+
+	io_buf = dvobjpriv->usb_vendor_req_buf;
+
+	status = usb_control_msg_recv(udev, 0, REALTEK_USB_VENQT_CMD_REQ,
+				      REALTEK_USB_VENQT_READ, addr,
+				      REALTEK_USB_VENQT_CMD_IDX, io_buf,
+				      size, RTW_USB_CONTROL_MSG_TIMEOUT,
+				      GFP_KERNEL);
+	if (!status) {
+		/*  Success this control transfer. */
+		rtw_reset_continual_urb_error(dvobjpriv);
+		memcpy(data, io_buf, size);
+		goto mutex_unlock;
+	}
+	/*  error cases */
+	if (status == (-ESHUTDOWN || -ENODEV || -ENOENT)) {
+		/*
+		 * device or controller has been disabled due to
+		 * some problem that could not be worked around,
+		 * device or bus doesn’t exist, endpoint does not
+		 * exist or is not enabled.
+		 */
+		adapt->bSurpriseRemoved = true;
+			goto mutex_unlock;
+	}
+	GET_HAL_DATA(adapt)->srestpriv.wifi_error_status = USB_VEN_REQ_CMD_FAIL;
+	if (rtw_inc_and_chk_continual_urb_error(dvobjpriv)) {
+		adapt->bSurpriseRemoved = true;
+		goto mutex_unlock;
+	}
+mutex_unlock:
+	mutex_unlock(&dvobjpriv->usb_vendor_req_mutex);
+exit:
+	return status;
+}
+
 u8 rtw_read8(struct adapter *adapter, u32 addr)
 {
 	u8 data;
@@ -96,7 +146,7 @@ u8 rtw_read8(struct adapter *adapter, u32 addr)
 	struct intf_hdl *intfhdl = &io_priv->intf;
 	u16 address = (u16)(addr & 0xffff);
 
-	usbctrl_vendorreq(intfhdl, address, &data, 1, REALTEK_USB_VENQT_READ);
+	usb_read(intfhdl, address, &data, 1);
 
 	return data;
 }
@@ -108,7 +158,7 @@ u16 rtw_read16(struct adapter *adapter, u32 addr)
 	struct io_priv *io_priv = &adapter->iopriv;
 	struct intf_hdl *intfhdl = &io_priv->intf;
 
-	usbctrl_vendorreq(intfhdl, address, &data, 2, REALTEK_USB_VENQT_READ);
+	usb_read(intfhdl, address, &data, 2);
 
 	return le16_to_cpu(data);
 }
@@ -120,7 +170,7 @@ u32 rtw_read32(struct adapter *adapter, u32 addr)
 	struct io_priv *io_priv = &adapter->iopriv;
 	struct intf_hdl *intfhdl = &io_priv->intf;
 
-	usbctrl_vendorreq(intfhdl, address, &data, 4, REALTEK_USB_VENQT_READ);
+	usb_read(intfhdl, address, &data, 4);
 
 	return le32_to_cpu(data);
 }
-- 
2.33.0