serial/imx: support to handle break character
The imx UART hardware controller can identify BREAK character and the
imx_set_termios() can accept BRKINT set by users, but current existing
imx_rxint() can't pass BREAK character and TTY_BREAK to the tty layer
as other serial drivers do (8250.c omap_serial.c).
Here add code to handle BREAK character and pass it to tty layer.
To detect error occurrence, i use URXD_ERR to replace (URXD_OVRRUN |
URXD_FRMERR | ...) because any kind of error occurs, URXD_ERR will
always be set to 1.
I put the URXD_BRK to the first place to check since when BREAK error
occurs, not only URXD_BRK is set to 1, but also URXD_PRERR and
URXD_FRMERR are all set to 1. This arrangement can filter out fake
parity and frame errors when BREAK error occurs.
Signed-off-by: Hui Wang <jason77.wang@gmail.com>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index 7e91b3d..54ffdc6 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -508,8 +508,10 @@
if (uart_handle_sysrq_char(&sport->port, (unsigned char)rx))
continue;
- if (rx & (URXD_PRERR | URXD_OVRRUN | URXD_FRMERR) ) {
- if (rx & URXD_PRERR)
+ if (unlikely(rx & URXD_ERR)) {
+ if (rx & URXD_BRK)
+ sport->port.icount.brk++;
+ else if (rx & URXD_PRERR)
sport->port.icount.parity++;
else if (rx & URXD_FRMERR)
sport->port.icount.frame++;
@@ -524,7 +526,9 @@
rx &= sport->port.read_status_mask;
- if (rx & URXD_PRERR)
+ if (rx & URXD_BRK)
+ flg = TTY_BREAK;
+ else if (rx & URXD_PRERR)
flg = TTY_PARITY;
else if (rx & URXD_FRMERR)
flg = TTY_FRAME;