Commit 1ded7ea4 authored Feb 20, 2009 by Ming Lei Committed by Greg Kroah-Hartman Mar 24, 2009

USB: ch341 serial: fix port number changed after resume



This patch fixes the following bug:
	.plug ch341 usb serial port into a hub port;
	.ch341 driver bound to the device and /dev/ttyUSB0 comes
	.open /dev/ttyUSB0 by minicom and we can use the serial successfully
	.suspend the ch341 usb serial device(such as: echo suspend > power/level)
	.resume the ch341 usb serial device (such as: echo on > power/level)
	.new port /dev/ttyUSB1 comes ,and the original /dev/ttyUSB0 still exists,
but is no longer usable by minicom

The patch adds suspend and resume callback to ch341 usb driver to prevent it
from unbinding during suspend. The /dev/ttyUSB0 is not released until being
closed, so /dev/ttyUSB1 comes after resume, and the original /dev/ttyUSB0 is
no longer usable by minicom. It is really a mess for a minicom user.

This patch also adds the reset_resume callback to make it usable after resuming
from STR or hibernation, for generally STR or hibernation will make the vbus
of root-hub lost.

Finally enable the driver's supports_autosuspend, for the device is in working
order with it.

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

parent a227fd7d

drivers/usb/serial/ch341.c

+22 −0

Original line number	Diff line number	Diff line
		@@ -529,12 +529,34 @@ static int ch341_tiocmget(struct tty_struct tty, struct file file)
		return result;
		}


		static int ch341_reset_resume(struct usb_interface *intf)
		{
		struct usb_device *dev = interface_to_usbdev(intf);
		struct usb_serial *serial = NULL;
		struct ch341_private *priv;

		serial = usb_get_intfdata(intf);
		priv = usb_get_serial_port_data(serial->port[0]);

		/reconfigure ch341 serial port after bus-reset/
		ch341_configure(dev, priv);

		usb_serial_resume(intf);

		return 0;
		}

		static struct usb_driver ch341_driver = {
		.name = "ch341",
		.probe = usb_serial_probe,
		.disconnect = usb_serial_disconnect,
		.suspend = usb_serial_suspend,
		.resume = usb_serial_resume,
		.reset_resume = ch341_reset_resume,
		.id_table = id_table,
		.no_dynamic_id = 1,
		.supports_autosuspend = 1,
		};

		static struct usb_serial_driver ch341_device = {

Admin message