From 4379460a832fe256b28a811ed28c94bd3f055ecf Mon Sep 17 00:00:00 2001
From: Linus Walleij <linus.walleij@linaro.org>
Date: Wed, 26 Sep 2012 17:21:36 +0200
Subject: [PATCH] --- yaml --- r: 325790 b: refs/heads/master c:
 c5dd553b9fd069892c9e2de734f4f604e280fa7a h: refs/heads/master v: v3

---
 [refs]                                |  2 +-
 trunk/drivers/tty/serial/amba-pl011.c | 15 ++++++++++++++-
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/[refs] b/[refs]
index 3a47d028c173..85dd8bff8b3b 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 91f61ce24f95f6d5f96efb56e0a8633e19184289
+refs/heads/master: c5dd553b9fd069892c9e2de734f4f604e280fa7a
diff --git a/trunk/drivers/tty/serial/amba-pl011.c b/trunk/drivers/tty/serial/amba-pl011.c
index cede93876649..925eb8813a45 100644
--- a/trunk/drivers/tty/serial/amba-pl011.c
+++ b/trunk/drivers/tty/serial/amba-pl011.c
@@ -1595,13 +1595,26 @@ pl011_set_termios(struct uart_port *port, struct ktermios *termios,
 			old_cr &= ~ST_UART011_CR_OVSFACT;
 	}
 
+	/*
+	 * Workaround for the ST Micro oversampling variants to
+	 * increase the bitrate slightly, by lowering the divisor,
+	 * to avoid delayed sampling of start bit at high speeds,
+	 * else we see data corruption.
+	 */
+	if (uap->vendor->oversampling) {
+		if ((baud >= 3000000) && (baud < 3250000) && (quot > 1))
+			quot -= 1;
+		else if ((baud > 3250000) && (quot > 2))
+			quot -= 2;
+	}
 	/* Set baud rate */
 	writew(quot & 0x3f, port->membase + UART011_FBRD);
 	writew(quot >> 6, port->membase + UART011_IBRD);
 
 	/*
 	 * ----------v----------v----------v----------v-----
-	 * NOTE: MUST BE WRITTEN AFTER UARTLCR_M & UARTLCR_L
+	 * NOTE: lcrh_tx and lcrh_rx MUST BE WRITTEN AFTER
+	 * UART011_FBRD & UART011_IBRD.
 	 * ----------^----------^----------^----------^-----
 	 */
 	writew(lcr_h, port->membase + uap->lcrh_rx);