sh: drain and wait for early printk

Drain by waiting for all characters to be sent, and make sure to
wait a little bit after setting up the baud rate.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 6 insertions, 0 deletions

diff --git a/arch/sh/kernel/early_printk.c b/arch/sh/kernel/early_printk.c
index 18ca249e8409..11b4c85999b7 100644
--- a/arch/sh/kernel/early_printk.c
+++ b/arch/sh/kernel/early_printk.c
@@ -143,6 +143,7 @@ static void scif_sercon_init(char *s)
 {
         struct uart_port *port = &scif_port;
         unsigned baud = DEFAULT_BAUD;
+        unsigned int status;
         char *e;
 
         if (*s == ',')
@@ -161,12 +162,17 @@ static void scif_sercon_init(char *s)
                         baud = DEFAULT_BAUD;
         }
 
+        do {
+                status = sci_in(port, SCxSR);
+        } while (!(status & SCxSR_TEND(port)));
+
         sci_out(port, SCSCR, 0);         /* TE=0, RE=0 */
         sci_out(port, SCSMR, 0);
 
         /* Set baud rate */
         sci_out(port, SCBRR, (CONFIG_SH_PCLK_FREQ + 16 * baud) /
                 (32 * baud) - 1);
+        udelay((1000000+(baud-1)) / baud); /* Wait one bit interval */
 
         sci_out(port, SCFCR, 12);
         sci_out(port, SCFCR, 8);