USB: serial: ftdi_sio: clean up receive processing

[ Upstream commit ce054039ba5e47b75a3be02a00274e52b06a6456 ]

Clean up receive processing by dropping the character pointer and
keeping the length argument unchanged throughout the function.

Also make it more apparent that sysrq processing can consume a
characters by adding an explicit continue.

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
index 2583d21..0c8b24f 100644 (file)
--- a/drivers/usb/serial/ftdi_sio.c
+++ b/drivers/usb/serial/ftdi_sio.c
@@ -2054,7 +2054,6 @@ static int ftdi_process_packet(struct usb_serial_port *port,
                struct ftdi_private *priv, unsigned char *buf, int len)
 {
        unsigned char status;
-       unsigned char *ch;
        int i;
        char flag;
 
@@ -2097,8 +2096,7 @@ static int ftdi_process_packet(struct usb_serial_port *port,
        else
                priv->transmit_empty = 0;
 
-       len -= 2;
-       if (!len)
+       if (len == 2)
                return 0;       /* status only */
 
        /*
@@ -2127,19 +2125,20 @@ static int ftdi_process_packet(struct usb_serial_port *port,
                }
        }
 
-       port->icount.rx += len;
-       ch = buf + 2;
+       port->icount.rx += len - 2;
 
        if (port->port.console && port->sysrq) {
-               for (i = 0; i < len; i++, ch++) {
-                       if (!usb_serial_handle_sysrq_char(port, *ch))
-                               tty_insert_flip_char(&port->port, *ch, flag);
+               for (i = 2; i < len; i++) {
+                       if (usb_serial_handle_sysrq_char(port, buf[i]))
+                               continue;
+                       tty_insert_flip_char(&port->port, buf[i], flag);
                }
        } else {
-               tty_insert_flip_string_fixed_flag(&port->port, ch, flag, len);
+               tty_insert_flip_string_fixed_flag(&port->port, buf + 2, flag,
+                               len - 2);
        }
 
-       return len;
+       return len - 2;
 }
 
 static void ftdi_process_read_urb(struct urb *urb)