From: Nye Liu <nyet@mrv.com>
Before setting STOP_TX, set _brkcr to 0 so the SMC does not send a break

character. The driver appears to properly re-initialize _brkcr when the SMC is

restarted.
Do not interrupt RX/TX when the termios is being adjusted; it results in

corrupted characters appearing on the line.
Signed-off-by: Nye Liu <nyet@mrv.com>
---
diff --git a/drivers/serial/cpm_uart/cpm_uart_core.c b/drivers/serial/cpm_uart/cpm_uart_core.c

index a19dc7e..babd06b 100644

--- a/drivers/serial/cpm_uart/cpm_uart_core.c

+++ b/drivers/serial/cpm_uart/cpm_uart_core.c

@@ -476,10 +476,13 @@ static void cpm_uart_shutdown(struct uart_port *port)

 		}
 		/* Shut them really down and reinit buffer descriptors */

-		if (IS_SMC(pinfo))

+		if (IS_SMC(pinfo)) {

+			out_be16(&pinfo->smcup->smc_brkcr, 0);

 			cpm_line_cr_cmd(pinfo, CPM_CR_STOP_TX);

-		else

+		} else {

+			out_be16(&pinfo->sccup->scc_brkcr, 0);

 			cpm_line_cr_cmd(pinfo, CPM_CR_GRA_STOP_TX);

+		}
 		cpm_uart_initbd(pinfo);

 	}

@@ -590,9 +593,11 @@ static void cpm_uart_set_termios(struct uart_port *port,

 		 * enables, because we want to put them back if they were

 		 * present.

 		 */

-		prev_mode = in_be16(&smcp->smc_smcmr);

-		out_be16(&smcp->smc_smcmr, smcr_mk_clen(bits) | cval | SMCMR_SM_UART);

-		setbits16(&smcp->smc_smcmr, (prev_mode & (SMCMR_REN | SMCMR_TEN)));

+		prev_mode = in_be16(&smcp->smc_smcmr) & (SMCMR_REN | SMCMR_TEN);

+		/* Output in *one* operation, so we don't interrupt RX/TX if they

+		 * were already enabled. */

+		out_be16(&smcp->smc_smcmr, smcr_mk_clen(bits) | cval |

+		    SMCMR_SM_UART | prev_mode);

 	} else {

 		out_be16(&sccp->scc_psmr, (sbits << 12) | scval);

 	}

@@ -1324,12 +1329,14 @@ static int __init cpm_uart_console_setup(struct console *co, char *options)

 	udbg_putc = NULL;

 #endif
-	cpm_line_cr_cmd(pinfo, CPM_CR_STOP_TX);

-

 	if (IS_SMC(pinfo)) {

+		out_be16(&pinfo->smcup...
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