diff options
| author | Karoly Pados <pados@pados.hu> | 2019-01-14 13:30:03 +0100 |
|---|---|---|
| committer | Johan Hovold <johan@kernel.org> | 2019-01-14 14:40:11 +0100 |
| commit | a8eda9fa1bd84065b75bfa81bf675a7af9055478 (patch) | |
| tree | 941a79177e89f85bae6de6cf2022df85b9902f88 | |
| parent | b81c2c33eab79dfd3650293b2227ee5c6036585c (diff) | |
| download | linux-a8eda9fa1bd84065b75bfa81bf675a7af9055478.tar.bz2 | |
USB: serial: ftdi_sio: fix GPIO not working in autosuspend
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>
| -rw-r--r-- | drivers/usb/serial/ftdi_sio.c | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c index 1ab2a6191013..77ef4c481f3c 100644 --- 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_serial_port *port, u8 mode) 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_serial_port *port, u8 mode) val, result); } + usb_autopm_put_interface(serial->interface); + return result; } @@ -1846,9 +1852,15 @@ static int ftdi_read_cbus_pins(struct usb_serial_port *port) 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 usb_serial_port *port) } kfree(buf); + usb_autopm_put_interface(serial->interface); return result; } |