| From a8eda9fa1bd84065b75bfa81bf675a7af9055478 Mon Sep 17 00:00:00 2001 |
| From: Karoly Pados <pados@pados.hu> |
| Date: Mon, 14 Jan 2019 13:30:03 +0100 |
| Subject: USB: serial: ftdi_sio: fix GPIO not working in autosuspend |
| |
| From: Karoly Pados <pados@pados.hu> |
| |
| commit a8eda9fa1bd84065b75bfa81bf675a7af9055478 upstream. |
| |
| There is a bug in the current GPIO code for ftdi_sio: it failed to take USB |
| autosuspend into account. If the device is in autosuspend, calls to |
| usb_control_msg() fail with -EHOSTUNREACH. Because the standard value for |
| autosuspend timeout is usually 2-5 seconds, this made it almost impossible |
| to use the GPIOs on machines that have USB autosuspend enabled. This patch |
| fixes the issue by acquiring a PM lock on the device for the duration of |
| the USB transfers. Tested on an FT231X device. |
| |
| Signed-off-by: Karoly Pados <pados@pados.hu> |
| [ johan: simplify code somewhat ] |
| Fixes: ba93cc7da896 ("USB: serial: ftdi_sio: implement GPIO support for FT-X devices") |
| Cc: stable <stable@vger.kernel.org> # 4.20 |
| Signed-off-by: Johan Hovold <johan@kernel.org> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| drivers/usb/serial/ftdi_sio.c | 15 ++++++++++++++- |
| 1 file changed, 14 insertions(+), 1 deletion(-) |
| |
| --- a/drivers/usb/serial/ftdi_sio.c |
| +++ b/drivers/usb/serial/ftdi_sio.c |
| @@ -1783,6 +1783,10 @@ static int ftdi_set_bitmode(struct usb_s |
| int result; |
| u16 val; |
| |
| + result = usb_autopm_get_interface(serial->interface); |
| + if (result) |
| + return result; |
| + |
| val = (mode << 8) | (priv->gpio_output << 4) | priv->gpio_value; |
| result = usb_control_msg(serial->dev, |
| usb_sndctrlpipe(serial->dev, 0), |
| @@ -1795,6 +1799,8 @@ static int ftdi_set_bitmode(struct usb_s |
| val, result); |
| } |
| |
| + usb_autopm_put_interface(serial->interface); |
| + |
| return result; |
| } |
| |
| @@ -1846,9 +1852,15 @@ static int ftdi_read_cbus_pins(struct us |
| unsigned char *buf; |
| int result; |
| |
| + result = usb_autopm_get_interface(serial->interface); |
| + if (result) |
| + return result; |
| + |
| buf = kmalloc(1, GFP_KERNEL); |
| - if (!buf) |
| + if (!buf) { |
| + usb_autopm_put_interface(serial->interface); |
| return -ENOMEM; |
| + } |
| |
| result = usb_control_msg(serial->dev, |
| usb_rcvctrlpipe(serial->dev, 0), |
| @@ -1863,6 +1875,7 @@ static int ftdi_read_cbus_pins(struct us |
| } |
| |
| kfree(buf); |
| + usb_autopm_put_interface(serial->interface); |
| |
| return result; |
| } |