This is a note to let you know that I've just added the patch titled
USB: serial: ftdi_sio: fix GPIO not working in autosuspend
to my usb git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git in the usb-linus branch.
The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.
If you have any questions about this process, please let me know.
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
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 --- drivers/usb/serial/ftdi_sio.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-)
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; }