From: Ming Lei <tom.leiming@xxxxxxxxx>
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@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>
---
drivers/usb/serial/ch341.c | 22 ++++++++++++++++++++++
1 files changed, 22 insertions(+), 0 deletions(-)
diff --git a/drivers/usb/serial/ch341.c b/drivers/usb/serial/ch341.c
index d5ea679..ab4cc27 100644
--- a/drivers/usb/serial/ch341.c
+++ b/drivers/usb/serial/ch341.c
@@ -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 = {
--
1.6.2
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