USB: cypress_m8: 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>
This commit is contained in:
Johan Hovold 2014-01-02 22:49:26 +01:00 committed by Greg Kroah-Hartman
parent 2534be34c9
commit 7603381e3e
2 changed files with 5 additions and 1 deletions

View File

@ -1187,7 +1187,10 @@ static void cypress_read_int_callback(struct urb *urb)
if (priv->current_status != priv->prev_status) {
priv->diff_status |= priv->current_status ^
priv->prev_status;
wake_up_interruptible(&port->port.delta_msr_wait);
if (priv->diff_status & UART_MSR_MASK)
wake_up_interruptible(&port->port.delta_msr_wait);
priv->prev_status = priv->current_status;
}
spin_unlock_irqrestore(&priv->lock, flags);

View File

@ -66,6 +66,7 @@
#define CONTROL_RTS 0x10 /* request to send */
#define CONTROL_RESET 0x08 /* sent with output report */
#define UART_MSR_MASK 0xf0
#define UART_RI 0x80 /* ring indicator */
#define UART_CD 0x40 /* carrier detect */
#define UART_DSR 0x20 /* data set ready */