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@xxxxxxxxx>
Cc: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
Cc: Alan Cox <alan@xxxxxxxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxx>
---
drivers/tty/serial/imx.c | 10 +++++++---
1 files changed, 7 insertions(+), 3 deletions(-)
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 @@ static irqreturn_t imx_rxint(int irq, void *dev_id)
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 @@ static irqreturn_t imx_rxint(int irq, void *dev_id)
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;
--
1.7.6
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