Commit 5fd2b6ee authored by Geert Uytterhoeven's avatar Geert Uytterhoeven Committed by Greg Kroah-Hartman

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

Inspired by a patch in the BSP by Koji Matsuoka
Signed-off-by: default avatarGeert Uytterhoeven <>
Signed-off-by: default avatarGreg Kroah-Hartman <>
parent 755dd8aa
......@@ -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);
/* 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);
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