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,