From: Karoly Pados <pados@pados.hu> To: "Johan Hovold" <johan@kernel.org>, "Greg Kroah-Hartman" <gregkh@linuxfoundation.org>, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, "Loic Poulain" <loic.poulain@linaro.org> Cc: Karoly Pados <pados@pados.hu> Subject: [PATCH] USB: serial: ftdi_sio: Fix GPIO not working in autosuspend Date: Mon, 14 Jan 2019 13:30:03 +0100 [thread overview] Message-ID: <20190114123003.8228-1-pados@pados.hu> (raw) 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> --- Please consider backporting to 4.20.x, otherwise the GPIO driver is not really usable for anybody with USB autosuspend enabled (eg. many laptops), at least not without manual configuration. drivers/usb/serial/ftdi_sio.c | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c index 1ab2a6191013..01813dce37f2 100644 --- a/drivers/usb/serial/ftdi_sio.c +++ b/drivers/usb/serial/ftdi_sio.c @@ -1783,6 +1783,13 @@ static int ftdi_set_bitmode(struct usb_serial_port *port, u8 mode) int result; u16 val; + result = usb_autopm_get_interface(port->serial->interface); + if (result) { + dev_err(&port->serial->interface->dev, + "Failed to wake device from autosuspend.\n"); + 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 +1802,8 @@ static int ftdi_set_bitmode(struct usb_serial_port *port, u8 mode) val, result); } + usb_autopm_put_interface(port->serial->interface); + return result; } @@ -1846,9 +1855,18 @@ static int ftdi_read_cbus_pins(struct usb_serial_port *port) unsigned char *buf; int result; + result = usb_autopm_get_interface(port->serial->interface); + if (result) { + dev_err(&port->serial->interface->dev, + "Failed to wake device from autosuspend.\n"); + return result; + } + buf = kmalloc(1, GFP_KERNEL); - if (!buf) + if (!buf) { + usb_autopm_put_interface(port->serial->interface); return -ENOMEM; + } result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0), @@ -1863,6 +1881,7 @@ static int ftdi_read_cbus_pins(struct usb_serial_port *port) } kfree(buf); + usb_autopm_put_interface(port->serial->interface); return result; } -- 2.20.1
WARNING: multiple messages have this Message-ID (diff)
From: Karoly Pados <pados@pados.hu> To: Johan Hovold <johan@kernel.org>, Greg Kroah-Hartman <gregkh@linuxfoundation.org>, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Loic Poulain <loic.poulain@linaro.org> Cc: Karoly Pados <pados@pados.hu> Subject: USB: serial: ftdi_sio: Fix GPIO not working in autosuspend Date: Mon, 14 Jan 2019 13:30:03 +0100 [thread overview] Message-ID: <20190114123003.8228-1-pados@pados.hu> (raw) 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> --- Please consider backporting to 4.20.x, otherwise the GPIO driver is not really usable for anybody with USB autosuspend enabled (eg. many laptops), at least not without manual configuration. drivers/usb/serial/ftdi_sio.c | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c index 1ab2a6191013..01813dce37f2 100644 --- a/drivers/usb/serial/ftdi_sio.c +++ b/drivers/usb/serial/ftdi_sio.c @@ -1783,6 +1783,13 @@ static int ftdi_set_bitmode(struct usb_serial_port *port, u8 mode) int result; u16 val; + result = usb_autopm_get_interface(port->serial->interface); + if (result) { + dev_err(&port->serial->interface->dev, + "Failed to wake device from autosuspend.\n"); + 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 +1802,8 @@ static int ftdi_set_bitmode(struct usb_serial_port *port, u8 mode) val, result); } + usb_autopm_put_interface(port->serial->interface); + return result; } @@ -1846,9 +1855,18 @@ static int ftdi_read_cbus_pins(struct usb_serial_port *port) unsigned char *buf; int result; + result = usb_autopm_get_interface(port->serial->interface); + if (result) { + dev_err(&port->serial->interface->dev, + "Failed to wake device from autosuspend.\n"); + return result; + } + buf = kmalloc(1, GFP_KERNEL); - if (!buf) + if (!buf) { + usb_autopm_put_interface(port->serial->interface); return -ENOMEM; + } result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0), @@ -1863,6 +1881,7 @@ static int ftdi_read_cbus_pins(struct usb_serial_port *port) } kfree(buf); + usb_autopm_put_interface(port->serial->interface); return result; }
next reply other threads:[~2019-01-14 12:55 UTC|newest] Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-01-14 12:30 Karoly Pados [this message] 2019-01-14 12:30 ` USB: serial: ftdi_sio: Fix GPIO not working in autosuspend Karoly Pados 2019-01-14 13:48 ` [PATCH] " Johan Hovold 2019-01-14 13:48 ` Johan Hovold 2019-01-14 15:13 ` [PATCH] " Johan Hovold 2019-01-14 15:13 ` Johan Hovold
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