1 files changed, 24 insertions, 13 deletions

diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
index 9ced8937a8f3..fb0d537435eb 100644
--- a/drivers/usb/serial/ftdi_sio.c
+++ b/drivers/usb/serial/ftdi_sio.c
@@ -2123,6 +2123,20 @@ static void ftdi_set_termios(struct tty_struct *tty,
                 termios->c_cflag |= CRTSCTS;
         }
 
+        /*
+         * All FTDI UART chips are limited to CS7/8. We won't pretend to
+         * support CS5/6 and revert the CSIZE setting instead.
+         */
+        if ((C_CSIZE(tty) != CS8) && (C_CSIZE(tty) != CS7)) {
+                dev_warn(ddev, "requested CSIZE setting not supported\n");
+
+                termios->c_cflag &= ~CSIZE;
+                if (old_termios)
+                        termios->c_cflag |= old_termios->c_cflag & CSIZE;
+                else
+                        termios->c_cflag |= CS8;
+        }
+
         cflag = termios->c_cflag;
 
         if (!old_termios)
@@ -2159,19 +2173,16 @@ no_skip:
         } else {
                 urb_value |= FTDI_SIO_SET_DATA_PARITY_NONE;
         }
-        if (cflag & CSIZE) {
-                switch (cflag & CSIZE) {
-                case CS7:
-                        urb_value |= 7;
-                        dev_dbg(ddev, "Setting CS7\n");
-                        break;
-                case CS8:
-                        urb_value |= 8;
-                        dev_dbg(ddev, "Setting CS8\n");
-                        break;
-                default:
-                        dev_err(ddev, "CSIZE was set but not CS7-CS8\n");
-                }
+        switch (cflag & CSIZE) {
+        case CS7:
+                urb_value |= 7;
+                dev_dbg(ddev, "Setting CS7\n");
+                break;
+        default:
+        case CS8:
+                urb_value |= 8;
+                dev_dbg(ddev, "Setting CS8\n");
+                break;
         }
 
         /* This is needed by the break command since it uses the same command