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authorGeert Uytterhoeven <geert+renesas@glider.be>2016-06-26 11:20:21 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-06-26 10:57:13 -0700
commit5fd2b6ee7a319e0955acff96948fae57321b1f5a (patch)
tree07c134bb52fbd413e04e8acd1480a36b3e29cc6a /drivers/tty
parent755dd8aa12d162e40f3c5bd0031ad2f29ce6bc68 (diff)
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serial: sh-sci: Stop transfers in sci_shutdown()
Make sure the transmitter and receiver are stopped when shutting down the port, and related interrupts are disabled. Without this: - New input data may be received into the RX FIFO, possibly triggering a new RX DMA completion, - Transfers will still be enabled on a subsequent startup of the UART, before the UART's FIFOs have been reset, causing reading of stale data. Inspired by a patch in the BSP by Koji Matsuoka <koji.matsuoka.xm@renesas.com>. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
-rw-r--r--drivers/tty/serial/sh-sci.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index 432d9acabf7f..d86eee38aae6 100644
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -1989,6 +1989,7 @@ static void sci_shutdown(struct uart_port *port)
{
struct sci_port *s = to_sci_port(port);
unsigned long flags;
+ u16 scr;
dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
@@ -1998,6 +1999,9 @@ static void sci_shutdown(struct uart_port *port)
spin_lock_irqsave(&port->lock, flags);
sci_stop_rx(port);
sci_stop_tx(port);
+ /* Stop RX and TX, disable related interrupts, keep clock source */
+ scr = serial_port_in(port, SCSCR);
+ serial_port_out(port, SCSCR, scr & (SCSCR_CKE1 | SCSCR_CKE0));
spin_unlock_irqrestore(&port->lock, flags);
#ifdef CONFIG_SERIAL_SH_SCI_DMA