Merge branch 'stable-3.2' into pandora-3.2

[pandora-kernel.git] / drivers / tty / serial / amba-pl011.c

diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index 6da8cf8..fe9f111 100644 (file)
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -1627,13 +1627,26 @@ 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);