FAILED: patch "[PATCH] USB: serial: cp210x: fix GPIO in autosuspend" failed to apply to 4.14-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 4.14-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 7b0b644b9aa2de5032db0f468fddca091d0b7b90 Mon Sep 17 00:00:00 2001
From: Karoly Pados <pados@pados.hu>
Date: Sun, 17 Feb 2019 18:59:01 +0100
Subject: [PATCH] USB: serial: cp210x: fix GPIO in autosuspend

Current GPIO code in cp210x fails to take USB autosuspend into account,
making it practically impossible to use GPIOs with autosuspend enabled
without user configuration. Fix this like for ftdi_sio in a previous patch.
Tested on a CP2102N.

Signed-off-by: Karoly Pados <pados@pados.hu>
Fixes: cf5276ce7867 ("USB: serial: cp210x: Adding GPIO support for CP2105")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Johan Hovold <johan@kernel.org>

diff --git a/drivers/usb/serial/cp210x.c b/drivers/usb/serial/cp210x.c
index fac7a4547523..de076e866661 100644
--- a/drivers/usb/serial/cp210x.c
+++ b/drivers/usb/serial/cp210x.c
@@ -1370,8 +1370,13 @@ static int cp210x_gpio_get(struct gpio_chip *gc, unsigned int gpio)
 	if (priv->partnum == CP210X_PARTNUM_CP2105)
 		req_type = REQTYPE_INTERFACE_TO_HOST;
 
+	result = usb_autopm_get_interface(serial->interface);
+	if (result)
+		return result;
+
 	result = cp210x_read_vendor_block(serial, req_type,
 					  CP210X_READ_LATCH, &buf, sizeof(buf));
+	usb_autopm_put_interface(serial->interface);
 	if (result < 0)
 		return result;
 
@@ -1392,6 +1397,10 @@ static void cp210x_gpio_set(struct gpio_chip *gc, unsigned int gpio, int value)
 
 	buf.mask = BIT(gpio);
 
+	result = usb_autopm_get_interface(serial->interface);
+	if (result)
+		goto out;
+
 	if (priv->partnum == CP210X_PARTNUM_CP2105) {
 		result = cp210x_write_vendor_block(serial,
 						   REQTYPE_HOST_TO_INTERFACE,
@@ -1409,6 +1418,8 @@ static void cp210x_gpio_set(struct gpio_chip *gc, unsigned int gpio, int value)
 					 NULL, 0, USB_CTRL_SET_TIMEOUT);
 	}
 
+	usb_autopm_put_interface(serial->interface);
+out:
 	if (result < 0) {
 		dev_err(&serial->interface->dev, "failed to set GPIO value: %d\n",
 				result);