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Commit 5fd2b6ee authored by Geert Uytterhoeven's avatar Geert Uytterhoeven Committed by Greg Kroah-Hartman
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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: default avatarGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 755dd8aa

drivers/tty/serial/sh-sci.c

+4 −0
Original line number Diff line number Diff line
@@ -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