From: David Engraf <david.engraf@sysgo.com>
To: richard.genoud@gmail.com, gregkh@linuxfoundation.org,
jslaby@suse.com, nicolas.ferre@microchip.com,
alexandre.belloni@bootlin.com, ludovic.desroches@microchip.com
Cc: linux-serial@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org,
David Engraf <david.engraf@sysgo.com>
Subject: [PATCH v2] tty/serial: atmel: fix out of range clock divider handling
Date: Fri, 13 Dec 2019 15:03:01 +0100 [thread overview]
Message-ID: <20191213140301.16490-1-david.engraf@sysgo.com> (raw)
In-Reply-To: <1e2e3f63-84db-4b38-1bf1-85916116e0a2@sysgo.com>
Use MCK_DIV8 when the clock divider is > 65535. Unfortunately the mode
register was already written thus the clock selection is ignored.
Fix by doing the baud rate calulation before setting the mode.
Fixes: 5bf5635ac170 ("tty/serial: atmel: add fractional baud rate support")
Signed-off-by: David Engraf <david.engraf@sysgo.com>
---
drivers/tty/serial/atmel_serial.c | 43 ++++++++++++++++---------------
1 file changed, 22 insertions(+), 21 deletions(-)
diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index a8dc8af83f39..1ba9bc667e13 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -2270,27 +2270,6 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios,
mode |= ATMEL_US_USMODE_NORMAL;
}
- /* set the mode, clock divisor, parity, stop bits and data size */
- atmel_uart_writel(port, ATMEL_US_MR, mode);
-
- /*
- * when switching the mode, set the RTS line state according to the
- * new mode, otherwise keep the former state
- */
- if ((old_mode & ATMEL_US_USMODE) != (mode & ATMEL_US_USMODE)) {
- unsigned int rts_state;
-
- if ((mode & ATMEL_US_USMODE) == ATMEL_US_USMODE_HWHS) {
- /* let the hardware control the RTS line */
- rts_state = ATMEL_US_RTSDIS;
- } else {
- /* force RTS line to low level */
- rts_state = ATMEL_US_RTSEN;
- }
-
- atmel_uart_writel(port, ATMEL_US_CR, rts_state);
- }
-
/*
* Set the baud rate:
* Fractional baudrate allows to setup output frequency more
@@ -2317,6 +2296,28 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios,
if (!(port->iso7816.flags & SER_ISO7816_ENABLED))
atmel_uart_writel(port, ATMEL_US_BRGR, quot);
+
+ /* set the mode, clock divisor, parity, stop bits and data size */
+ atmel_uart_writel(port, ATMEL_US_MR, mode);
+
+ /*
+ * when switching the mode, set the RTS line state according to the
+ * new mode, otherwise keep the former state
+ */
+ if ((old_mode & ATMEL_US_USMODE) != (mode & ATMEL_US_USMODE)) {
+ unsigned int rts_state;
+
+ if ((mode & ATMEL_US_USMODE) == ATMEL_US_USMODE_HWHS) {
+ /* let the hardware control the RTS line */
+ rts_state = ATMEL_US_RTSDIS;
+ } else {
+ /* force RTS line to low level */
+ rts_state = ATMEL_US_RTSEN;
+ }
+
+ atmel_uart_writel(port, ATMEL_US_CR, rts_state);
+ }
+
atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_RSTSTA | ATMEL_US_RSTRX);
atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXEN | ATMEL_US_RXEN);
atmel_port->tx_stopped = false;
--
2.17.1
next prev parent reply other threads:[~2019-12-13 20:37 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-11 16:29 [PATCH] tty/serial: atmel: fix out of range clock divider handling David Engraf
2019-12-13 9:57 ` Richard Genoud
2019-12-13 13:49 ` David Engraf
2019-12-13 14:03 ` David Engraf [this message]
2019-12-13 16:07 ` [PATCH v2] " Greg KH
2019-12-16 8:34 ` David Engraf
2019-12-16 8:54 ` [PATCH v3] " David Engraf
2019-12-16 10:03 ` Richard Genoud
2019-12-16 10:26 ` Ludovic Desroches
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