Hello Troy,

On Tue, Feb 20, 2018 at 12:25:16PM -0800, Troy Kisky wrote:

quoted

quoted

@@ -1028,6 +1027,7 @@ static int start_rx_dma(struct imx_port *sport)
 
 static void clear_rx_errors(struct imx_port *sport)
 {
+	struct tty_port *port = &sport->port.state->port;
 	unsigned int status_usr1, status_usr2;
 
 	status_usr1 = readl(sport->port.membase + USR1);

@@ -1036,12 +1036,18 @@ static void clear_rx_errors(struct imx_port *sport)
 	if (status_usr2 & USR2_BRCD) {
 		sport->port.icount.brk++;
 		writel(USR2_BRCD, sport->port.membase + USR2);
-	} else if (status_usr1 & USR1_FRAMERR) {
-		sport->port.icount.frame++;
-		writel(USR1_FRAMERR, sport->port.membase + USR1);
-	} else if (status_usr1 & USR1_PARITYERR) {
-		sport->port.icount.parity++;
-		writel(USR1_PARITYERR, sport->port.membase + USR1);
+		if (tty_insert_flip_char(port, 0, TTY_BREAK) == 0)
+			sport->port.icount.buf_overrun++;
+		tty_flip_buffer_push(port);

I think this needs to call uart_handle_break() as imx_rxint() does. Not sure
how to properly handle SYSRQ in the dma case though.

SYSRQ is only for the console port, and console port is never dma. But UPF_SAK may be
an issue. I don't know enough about "Secure Attention Key" to say.


Should I add uart_handle_break anyway ?

You're right about both SYSRQ and SAK. I think uart_handle_break is the
right one for the latter.

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-K?nig            |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |