lkml.org 
[lkml]   [2022]   [Apr]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[RESEND PATCH -next] USB: serial: pl2303: implement reset_resume member
    Date
    From: Hongyu Xie <xiehongyu1@kylinos.cn>

    pl2303.c doesn't have reset_resume for hibernation.
    So needs_binding will be set to 1 duiring hibernation.
    usb_forced_unbind_intf will be called, and the port minor
    will be released (x in ttyUSBx).
    It works fine if you have only one USB-to-serial device.
    Assume you have 2 USB-to-serial device, nameing A and B.
    A gets a smaller minor(ttyUSB0), B gets a bigger one.
    And start to hibernate. When your PC is in hibernation,
    unplug device A. Then wake up your PC by pressing the
    power button. After waking up the whole system, device
    B gets ttyUSB0. This will casuse a problem if you were
    using those to ports(like opened two minicom process)
    before hibernation.
    So member reset_resume is needed in usb_serial_driver
    pl2303_device.
    Codes in pl2303_reset_resume are borrowed from pl2303_open.

    As a matter of fact, all driver under drivers/usb/serial
    has the same problem except ch341.c.

    Cc: stable@vger.kernel.org
    Signed-off-by: Hongyu Xie <xiehongyu1@kylinos.cn>
    Reported-by: sheng.huang <sheng.huang@ecastech.com>
    ---
    drivers/usb/serial/pl2303.c | 48 +++++++++++++++++++++++++++++++++++++
    1 file changed, 48 insertions(+)

    diff --git a/drivers/usb/serial/pl2303.c b/drivers/usb/serial/pl2303.c
    index 88b284d61681..7cc05123b88c 100644
    --- a/drivers/usb/serial/pl2303.c
    +++ b/drivers/usb/serial/pl2303.c
    @@ -1218,6 +1218,53 @@ static void pl2303_process_read_urb(struct urb *urb)
    tty_flip_buffer_push(&port->port);
    }

    +static int pl2303_configure(struct usb_serial *serial, struct pl2303_serial_private *priv)
    +{
    + struct usb_serial_port *port = serial->port[0];
    +
    + if (priv->quirks & PL2303_QUIRK_LEGACY) {
    + usb_clear_halt(serial->dev, port->write_urb->pipe);
    + usb_clear_halt(serial->dev, port->read_urb->pipe);
    + } else {
    + /* reset upstream data pipes */
    + if (priv->type == &pl2303_type_data[TYPE_HXN])
    + pl2303_vendor_write(serial, PL2303_HXN_RESET_REG,
    + PL2303_HXN_RESET_UPSTREAM_PIPE |
    + PL2303_HXN_RESET_DOWNSTREAM_PIPE);
    + else {
    + pl2303_vendor_write(serial, 8, 0);
    + pl2303_vendor_write(serial, 9, 0);
    + }
    + }
    + return 0;
    +}
    +
    +static int pl2303_reset_resume(struct usb_serial *serial)
    +{
    + struct usb_serial_port *port = serial->port[0];
    + struct pl2303_serial_private *priv = usb_get_serial_port_data(port);
    + struct tty_struct *tty = tty_port_tty_get(&port->port);
    + int ret;
    +
    + /* reconfigure pl2303 serial port after bus-reset */
    + pl2303_configure(serial, priv);
    +
    + /* Setup termios */
    + if (tty)
    + pl2303_set_termios(tty, port, NULL);
    +
    + if (tty_port_initialized(&port->port)) {
    + ret = usb_submit_urb(port->interrupt_in_urb, GFP_NOIO);
    + if (ret) {
    + dev_err(&port->dev, "failed to submit interrupt urb: %d\n",
    + ret);
    + return ret;
    + }
    + }
    +
    + return usb_serial_generic_resume(serial);
    +}
    +
    static struct usb_serial_driver pl2303_device = {
    .driver = {
    .owner = THIS_MODULE,
    @@ -1246,6 +1293,7 @@ static struct usb_serial_driver pl2303_device = {
    .release = pl2303_release,
    .port_probe = pl2303_port_probe,
    .port_remove = pl2303_port_remove,
    + .reset_resume = pl2303_reset_resume,
    };

    static struct usb_serial_driver * const serial_drivers[] = {
    --
    2.25.1
    \
     
     \ /
      Last update: 2022-04-19 08:57    [W:2.672 / U:0.004 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site