[PATCH v6 17/19] staging: r8188eu: Shorten calls chains of rtw_read*()

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

Shorten the calls chains 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>
---
 drivers/staging/r8188eu/hal/usb_ops_linux.c | 60 +++++++++++++++++++--
 1 file changed, 57 insertions(+), 3 deletions(-)

diff --git a/drivers/staging/r8188eu/hal/usb_ops_linux.c b/drivers/staging/r8188eu/hal/usb_ops_linux.c
index d87da84eca07..ef35358cf2d3 100644
--- a/drivers/staging/r8188eu/hal/usb_ops_linux.c
+++ b/drivers/staging/r8188eu/hal/usb_ops_linux.c
@@ -89,13 +89,67 @@ 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)
+{
+	struct adapter *adapt = intfhdl->padapter;
+	struct dvobj_priv *dvobjpriv = adapter_to_dvobj(adapt);
+	struct usb_device *udev = dvobjpriv->pusbdev;
+	int status;
+	u8 *io_buf; /* Pointer to I/O buffer */
+
+	if (adapt->bSurpriseRemoved || adapt->pwrctrlpriv.pnp_bstop_trx)
+		return -EPERM;
+
+	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 == -ESHUTDOWN ||
+	    status == -ENODEV ||
+	    status == -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;
+	}
+
+	if (status < 0) {
+		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;
+	}
+
+	rtw_reset_continual_urb_error(dvobjpriv);
+	memcpy(data, io_buf, size);
+
+mutex_unlock:
+	mutex_unlock(&dvobjpriv->usb_vendor_req_mutex);
+
+	return status;
+}
+
 u8 rtw_read8(struct adapter *adapter, u32 addr)
 {
 	struct io_priv *io_priv = &adapter->iopriv;
 	struct intf_hdl *intfhdl = &io_priv->intf;
 	u16 address = addr & 0xffff;
 	u8 data;
-	usbctrl_vendorreq(intfhdl, address, &data, 1, REALTEK_USB_VENQT_READ);
+
+	usb_read(intfhdl, address, &data, 1);
 
 	return data;
 }
@@ -107,7 +161,7 @@ u16 rtw_read16(struct adapter *adapter, u32 addr)
 	u16 address = addr & 0xffff;
 	__le16 data;
 
-	usbctrl_vendorreq(intfhdl, address, &data, 2, REALTEK_USB_VENQT_READ);
+	usb_read(intfhdl, address, &data, 2);
 
 	return le16_to_cpu(data);
 }
@@ -119,7 +173,7 @@ u32 rtw_read32(struct adapter *adapter, u32 addr)
 	u16 address = addr & 0xffff;
 	__le32 data;
 
-	usbctrl_vendorreq(intfhdl, address, &data, 4, REALTEK_USB_VENQT_READ);
+	usb_read(intfhdl, address, &data, 4);
 
 	return le32_to_cpu(data);
 }
-- 
2.33.0