target/linux/brcm2708/patches-4.14/950-0438-sc16is7xx-Don-t-spin-if-no-data-received.patch

   1 From 15cbb4515b766b5efc48bc53b1f83c4211c671a4 Mon Sep 17 00:00:00 2001
   2 From: Phil Elwell <phil@raspberrypi.org>
   3 Date: Tue, 6 Nov 2018 12:57:48 +0000
   4 Subject: [PATCH 438/454] sc16is7xx: Don't spin if no data received
   5
   6 See: https://github.com/raspberrypi/linux/issues/2676
   7
   8 Signed-off-by: Phil Elwell <phil@raspberrypi.org>
   9 ---
  10  drivers/tty/serial/sc16is7xx.c | 2 ++
  11  1 file changed, 2 insertions(+)
  12
  13 --- a/drivers/tty/serial/sc16is7xx.c
  14 +++ b/drivers/tty/serial/sc16is7xx.c
  15 @@ -701,6 +701,8 @@ static bool sc16is7xx_port_irq(struct sc
  16                         rxlen = sc16is7xx_port_read(port, SC16IS7XX_RXLVL_REG);
  17                         if (rxlen)
  18                                 sc16is7xx_handle_rx(port, rxlen, iir);
  19 +                       else
  20 +                               return false;
  21                         break;
  22                 case SC16IS7XX_IIR_THRI_SRC:
  23                         sc16is7xx_handle_tx(port);