[SUNSAB]: Defer register updates until transmitter is idle.
The chip can emit garbage characters if we touch the
settings while characters are going out.
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/serial/sunsab.h b/drivers/serial/sunsab.h
index 686086f..b78e1f7 100644
--- a/drivers/serial/sunsab.h
+++ b/drivers/serial/sunsab.h
@@ -126,6 +126,7 @@
/* irqflags bits */
#define SAB82532_ALLS 0x00000001
#define SAB82532_XPR 0x00000002
+#define SAB82532_REGS_PENDING 0x00000004
/* RFIFO Status Byte */
#define SAB82532_RSTAT_PE 0x80