FAILED: patch "[PATCH] USB: serial: cp210x: enable usb generic throttle/unthrottle" failed to apply to 4.4-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 4387b3dbb079d482d3c2b43a703ceed4dd27ed28 Mon Sep 17 00:00:00 2001
From: Brant Merryman <brant.merryman@silabs.com>
Date: Fri, 26 Jun 2020 04:22:58 +0000
Subject: [PATCH] USB: serial: cp210x: enable usb generic throttle/unthrottle

Assign the .throttle and .unthrottle functions to be generic function
in the driver structure to prevent data loss that can otherwise occur
if the host does not enable USB throttling.

Signed-off-by: Brant Merryman <brant.merryman@silabs.com>
Co-developed-by: Phu Luu <phu.luu@silabs.com>
Signed-off-by: Phu Luu <phu.luu@silabs.com>
Link: https://lore.kernel.org/r/57401AF3-9961-461F-95E1-F8AFC2105F5E@silabs.com
[ johan: fix up tags ]
Fixes: 39a66b8d22a3 ("[PATCH] USB: CP2101 Add support for flow control")
Cc: stable <stable@vger.kernel.org>     # 2.6.12
Signed-off-by: Johan Hovold <johan@kernel.org>

diff --git a/drivers/usb/serial/cp210x.c b/drivers/usb/serial/cp210x.c
index f5143eedbc48..bcceb4ad8be0 100644
--- a/drivers/usb/serial/cp210x.c
+++ b/drivers/usb/serial/cp210x.c
@@ -272,6 +272,8 @@ static struct usb_serial_driver cp210x_device = {
 	.break_ctl		= cp210x_break_ctl,
 	.set_termios		= cp210x_set_termios,
 	.tx_empty		= cp210x_tx_empty,
+	.throttle		= usb_serial_generic_throttle,
+	.unthrottle		= usb_serial_generic_unthrottle,
 	.tiocmget		= cp210x_tiocmget,
 	.tiocmset		= cp210x_tiocmset,
 	.attach			= cp210x_attach,