USB: serial: cp210x: clean up CRTSCTS flag code

The CRTSCTS flag code cleared (and inconsistently) bits unrelated to
CRTSCTS functionality. It was also harder than necessary to read.

Signed-off-by: Konstantin Shkolnyy <konstantin.shkolnyy@gmail.com>
Signed-off-by: Johan Hovold <johan@kernel.org>

diff --git a/drivers/usb/serial/cp210x.c b/drivers/usb/serial/cp210x.c
index a33a4265125d96183b5b83e808e22742f2ebabe7..df1808201207fe06e6e8845a15b9520f06608b37 100644 (file)
--- a/drivers/usb/serial/cp210x.c
+++ b/drivers/usb/serial/cp210x.c
@@ -995,34 +995,22 @@ static void cp210x_set_termios(struct tty_struct *tty,
                dev_dbg(dev, "%s - read ulControlHandshake=0x%08x, ulFlowReplace=0x%08x\n",
                                __func__, ctl_hs, flow_repl);
 
+               ctl_hs &= ~CP210X_SERIAL_DSR_HANDSHAKE;
+               ctl_hs &= ~CP210X_SERIAL_DCD_HANDSHAKE;
+               ctl_hs &= ~CP210X_SERIAL_DSR_SENSITIVITY;
+               ctl_hs &= ~CP210X_SERIAL_DTR_MASK;
+               ctl_hs |= CP210X_SERIAL_DTR_SHIFT(CP210X_SERIAL_DTR_ACTIVE);
                if (cflag & CRTSCTS) {
-                       ctl_hs &= ~(CP210X_SERIAL_DTR_MASK |
-                                       CP210X_SERIAL_CTS_HANDSHAKE |
-                                       CP210X_SERIAL_DSR_HANDSHAKE |
-                                       CP210X_SERIAL_DCD_HANDSHAKE |
-                                       CP210X_SERIAL_DSR_SENSITIVITY);
-                       ctl_hs |= CP210X_SERIAL_DTR_SHIFT(
-                                       CP210X_SERIAL_DTR_ACTIVE);
                        ctl_hs |= CP210X_SERIAL_CTS_HANDSHAKE;
-                       /*
-                        * FIXME: Why clear bits unrelated to flow control.
-                        * Why clear CP210X_SERIAL_XOFF_CONTINUE which is
-                        * never set
-                        */
-                       flow_repl = 0;
+
+                       flow_repl &= ~CP210X_SERIAL_RTS_MASK;
                        flow_repl |= CP210X_SERIAL_RTS_SHIFT(
                                        CP210X_SERIAL_RTS_FLOW_CTL);
                        dev_dbg(dev, "%s - flow control = CRTSCTS\n", __func__);
                } else {
-                       ctl_hs &= ~(CP210X_SERIAL_DTR_MASK |
-                                       CP210X_SERIAL_CTS_HANDSHAKE |
-                                       CP210X_SERIAL_DSR_HANDSHAKE |
-                                       CP210X_SERIAL_DCD_HANDSHAKE |
-                                       CP210X_SERIAL_DSR_SENSITIVITY);
-                       ctl_hs |= CP210X_SERIAL_DTR_SHIFT(
-                                       CP210X_SERIAL_DTR_ACTIVE);
-                       /* FIXME: Why clear bits unrelated to flow control */
-                       flow_repl &= 0xffffff00;
+                       ctl_hs &= ~CP210X_SERIAL_CTS_HANDSHAKE;
+
+                       flow_repl &= ~CP210X_SERIAL_RTS_MASK;
                        flow_repl |= CP210X_SERIAL_RTS_SHIFT(
                                        CP210X_SERIAL_RTS_ACTIVE);
                        dev_dbg(dev, "%s - flow control = NONE\n", __func__);