Only wake up MSR wait queue on actual modem-status changes.
Signed-off-by: Johan Hovold <jhovold@xxxxxxxxx>
---
drivers/usb/serial/pl2303.c | 17 ++++++++++-------
1 file changed, 10 insertions(+), 7 deletions(-)
diff --git a/drivers/usb/serial/pl2303.c b/drivers/usb/serial/pl2303.c
index 11de1f169308..64f093f16981 100644
--- a/drivers/usb/serial/pl2303.c
+++ b/drivers/usb/serial/pl2303.c
@@ -118,6 +118,7 @@ MODULE_DEVICE_TABLE(usb, id_table);
#define VENDOR_READ_REQUEST 0x01
#define UART_STATE_INDEX 8
+#define UART_STATE_MSR_MASK 0x8b
#define UART_STATE_TRANSIENT_MASK 0x74
#define UART_DCD 0x01
#define UART_DSR 0x02
@@ -828,15 +829,17 @@ static void pl2303_update_line_status(struct usb_serial_port *port,
if (status & UART_BREAK_ERROR)
usb_serial_handle_break(port);
- wake_up_interruptible(&port->port.delta_msr_wait);
-
- if (delta & UART_DCD) {
- tty = tty_port_tty_get(&port->port);
- if (tty) {
- usb_serial_handle_dcd_change(port, tty,
+ if (delta & UART_STATE_MSR_MASK) {
+ if (delta & UART_DCD) {
+ tty = tty_port_tty_get(&port->port);
+ if (tty) {
+ usb_serial_handle_dcd_change(port, tty,
status & UART_DCD);
- tty_kref_put(tty);
+ tty_kref_put(tty);
+ }
}
+
+ wake_up_interruptible(&port->port.delta_msr_wait);
}
}
--
1.8.3.2
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