We implement delta change for MSR counting. This patch is referenced
from ftdi_sio.c
Signed-off-by: Peter Hung <hpeter+linux_kernel@xxxxxxxxx>
---
drivers/usb/serial/f81232.c | 27 ++++++++++++++++++++++-----
1 file changed, 22 insertions(+), 5 deletions(-)
diff --git a/drivers/usb/serial/f81232.c b/drivers/usb/serial/f81232.c
index 94c05d7..5134a19 100644
--- a/drivers/usb/serial/f81232.c
+++ b/drivers/usb/serial/f81232.c
@@ -112,6 +112,7 @@ static void f81232_read_msr(struct usb_serial_port *port)
unsigned long flags;
u8 current_msr, prev_msr;
u8 msr_mask = ~UART_MSR_ANY_DELTA;
+ u8 msr_changed_bit;
struct tty_struct *tty;
struct f81232_private *priv = usb_get_serial_port_data(port);
@@ -141,14 +142,30 @@ static void f81232_read_msr(struct usb_serial_port *port)
!((prev_msr ^ current_msr) & msr_mask))
return;
- tty = tty_port_tty_get(&port->port);
- if (tty) {
- if (current_msr & UART_MSR_DDCD) {
+ /* find checked delta bits set */
+ msr_changed_bit =
+ (current_msr & UART_MSR_ANY_DELTA) << 4;
+
+ /* append with not delta but changed bits */
+ msr_changed_bit |= (prev_msr ^ current_msr) & msr_mask;
+
+ if (msr_changed_bit & UART_MSR_CTS)
+ port->icount.cts++;
+ if (msr_changed_bit & UART_MSR_DSR)
+ port->icount.dsr++;
+ if (msr_changed_bit & UART_MSR_RI)
+ port->icount.rng++;
+ if (msr_changed_bit & UART_MSR_DCD) {
+
+ port->icount.dcd++;
+ tty = tty_port_tty_get(&port->port);
+ if (tty) {
+
usb_serial_handle_dcd_change(port, tty,
current_msr & UART_MSR_DCD);
- }
- tty_kref_put(tty);
+ tty_kref_put(tty);
+ }
}
wake_up_interruptible(&port->port.delta_msr_wait);
--
1.9.1
--
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