cpm1: don't send break on TX_STOP, don't interrupt RX/TX when adjusting termios param...

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.

Cc: Vitaly Bordug <vbordug@ru.mvista.com>
Cc: Scott Wood <scottwood@freescale.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/drivers/serial/cpm_uart/cpm_uart_core.c b/drivers/serial/cpm_uart/cpm_uart_core.c
index 1ff80de..a4f8692 100644 (file)
--- a/drivers/serial/cpm_uart/cpm_uart_core.c
+++ b/drivers/serial/cpm_uart/cpm_uart_core.c
@@ -435,10 +435,13 @@ 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);
        }
@@ -554,9 +557,11 @@ 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);
        }
@@ -1198,12 +1203,14 @@ 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->smc_brkcr, 0);
+               cpm_line_cr_cmd(pinfo, CPM_CR_STOP_TX);
                clrbits8(&pinfo->smcp->smc_smcm, SMCM_RX | SMCM_TX);
                clrbits16(&pinfo->smcp->smc_smcmr, SMCMR_REN | SMCMR_TEN);
        } else {
+               out_be16(&pinfo->sccup->scc_brkcr, 0);
+               cpm_line_cr_cmd(pinfo, CPM_CR_GRA_STOP_TX);
                clrbits16(&pinfo->sccp->scc_sccm, UART_SCCM_TX | UART_SCCM_RX);
                clrbits32(&pinfo->sccp->scc_gsmrl, SCC_GSMRL_ENR | SCC_GSMRL_ENT);
        }