[PATCH v4 1/3] USB: serial: cp210x: Fixed RTS mode setting by the CRTSCTS flag.

From: Konstantin Shkolnyy
Date: Tue May 03 2016 - 20:52:19 EST


A bug in the CRTSCTS handling caused RTS to alternate between
CRTSCTS=0 => "RTS transmits active signal" and
CRTSCTS=1 => "RTS receives flow control"
instead of
CRTSCTS=0 => "RTS is statically active" and
CRTSCTS=1 => "RTS receives flow control"
This only happened after first having enabled CRTSCTS.

Signed-off-by: Konstantin Shkolnyy <konstantin.shkolnyy@xxxxxxxxx>
---
v4:
Same series of patches, fixed names and defines by feedback.
v3:
Regenerated the patches correctly against the latest usb-next branch.
v2
Improved CRTSCTS fix by feedback. Dropped get_termios error handling fix.

drivers/usb/serial/cp210x.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/usb/serial/cp210x.c b/drivers/usb/serial/cp210x.c
index dd47823..fef7a51 100644
--- a/drivers/usb/serial/cp210x.c
+++ b/drivers/usb/serial/cp210x.c
@@ -967,8 +967,7 @@ static void cp210x_set_termios(struct tty_struct *tty,
} else {
modem_ctl[0] &= ~0x7B;
modem_ctl[0] |= 0x01;
- /* FIXME - OR here instead of assignment looks wrong */
- modem_ctl[4] |= 0x40;
+ modem_ctl[4] = 0x40;
dev_dbg(dev, "%s - flow control = NONE\n", __func__);
}

--
1.8.4.5