USB: safe_serial: straighten out read processing

Clean up read processing logic.

Tested using a cp210x device in a loopback setup.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 21 insertions, 22 deletions

diff --git a/drivers/usb/serial/safe_serial.c b/drivers/usb/serial/safe_serial.c
index d9af5c5ed9e8..a36e2313eed0 100644
--- a/drivers/usb/serial/safe_serial.c
+++ b/drivers/usb/serial/safe_serial.c
@@ -218,7 +218,9 @@ static void safe_process_read_urb(struct urb *urb)
         struct usb_serial_port *port = urb->context;
         unsigned char *data = urb->transfer_buffer;
         unsigned char length = urb->actual_length;
+        int actual_length;
         struct tty_struct *tty;
+        __u16 fcs;
 
         if (!length)
                 return;
@@ -227,30 +229,27 @@ static void safe_process_read_urb(struct urb *urb)
         if (!tty)
                 return;
 
-        if (safe) {
-                __u16 fcs;
-                fcs = fcs_compute10(data, length, CRC10_INITFCS);
-                if (!fcs) {
-                        int actual_length = data[length - 2] >> 2;
-                        if (actual_length <= (length - 2)) {
-                                dev_info(&urb->dev->dev, "%s - actual: %d\n",
-                                         __func__, actual_length);
-                                tty_insert_flip_string(tty,
-                                                        data, actual_length);
-                                tty_flip_buffer_push(tty);
-                        } else {
-                                dev_err(&port->dev,
-                                        "%s - inconsistent lengths %d:%d\n",
-                                        __func__, actual_length, length);
-                        }
-                } else {
-                        dev_err(&port->dev, "%s - bad CRC %x\n", __func__, fcs);
-                }
-        } else {
-                tty_insert_flip_string(tty, data, length);
-                tty_flip_buffer_push(tty);
+        if (!safe)
+                goto out;
+
+        fcs = fcs_compute10(data, length, CRC10_INITFCS);
+        if (fcs) {
+                dev_err(&port->dev, "%s - bad CRC %x\n", __func__, fcs);
+                goto err;
         }
 
+        actual_length = data[length - 2] >> 2;
+        if (actual_length > (length - 2)) {
+                dev_err(&port->dev, "%s - inconsistent lengths %d:%d\n",
+                                __func__, actual_length, length);
+                goto err;
+        }
+        dev_info(&urb->dev->dev, "%s - actual: %d\n", __func__, actual_length);
+        length = actual_length;
+out:
+        tty_insert_flip_string(tty, data, length);
+        tty_flip_buffer_push(tty);
+err:
         tty_kref_put(tty);
 }