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authorJohan Hovold <jhovold@gmail.com>2014-01-02 22:49:31 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-01-03 12:42:24 -0800
commitd984fe91a85e49841449b120cda5a50fed1fb126 (patch)
tree5a428e9c530ac64abdb17679d84674fb7a9f4464 /drivers/usb/serial/ch341.c
parentfd74b0b144d3e392b5269207ae4abba03f0adf59 (diff)
downloadlinux-d984fe91a85e49841449b120cda5a50fed1fb126.tar.bz2
USB: ch341: only wake up MSR queue on changes
Only wake up MSR wait queue on actual modem-status changes. Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/serial/ch341.c')
-rw-r--r--drivers/usb/serial/ch341.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/usb/serial/ch341.c b/drivers/usb/serial/ch341.c
index 025b7857a36c..acc88650ac0a 100644
--- a/drivers/usb/serial/ch341.c
+++ b/drivers/usb/serial/ch341.c
@@ -460,6 +460,9 @@ static void ch341_update_line_status(struct usb_serial_port *port,
if (data[1] & CH341_MULT_STAT)
dev_dbg(&port->dev, "%s - multiple status change\n", __func__);
+ if (!delta)
+ return;
+
if (delta & CH341_BIT_DCD) {
tty = tty_port_tty_get(&port->port);
if (tty) {