target/linux/bcm27xx/patches-6.1/950-1274-serial-sc16is7xx-Don-t-spin-if-no-data-received.patch

   1 From 58c600f728f2787e905eff2f678fa9cf09694004 Mon Sep 17 00:00:00 2001
   2 From: Phil Elwell <phil@raspberrypi.com>
   3 Date: Fri, 2 Feb 2024 15:41:29 +0000
   4 Subject: [PATCH 1274/1295] serial: sc16is7xx: Don't spin if no data received
   5
   6 There are multiple causes of interrupts, errors being one, and only the
   7 receipt of data warrants continued polling.
   8
   9 See: https://github.com/raspberrypi/linux/issues/2676
  10
  11 Signed-off-by: Phil Elwell <phil@raspberrypi.com>
  12 ---
  13  drivers/tty/serial/sc16is7xx.c | 2 ++
  14  1 file changed, 2 insertions(+)
  15
  16 --- a/drivers/tty/serial/sc16is7xx.c
  17 +++ b/drivers/tty/serial/sc16is7xx.c
  18 @@ -762,6 +762,8 @@ static bool sc16is7xx_port_irq(struct sc
  19
  20                 if (rxlen)
  21                         sc16is7xx_handle_rx(port, rxlen, iir);
  22 +               else
  23 +                       rc = false;
  24                 break;
  25                 /* CTSRTS interrupt comes only when CTS goes inactive */
  26         case SC16IS7XX_IIR_CTSRTS_SRC: