target/linux/brcm2708/patches-4.19/950-0138-sc16is7xx-Don-t-spin-if-no-data-received.patch


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From 3f8c7542e12f23f6be2cd7206fbf808409db2848 Mon Sep 17 00:00:00 2001
From: Phil Elwell <phil@raspberrypi.org>
Date: Tue, 6 Nov 2018 12:57:48 +0000
Subject: [PATCH] sc16is7xx: Don't spin if no data received

See: https://github.com/raspberrypi/linux/issues/2676

Signed-off-by: Phil Elwell <phil@raspberrypi.org>
---
 drivers/tty/serial/sc16is7xx.c | 2 ++
 1 file changed, 2 insertions(+)

--- a/drivers/tty/serial/sc16is7xx.c
+++ b/drivers/tty/serial/sc16is7xx.c
@@ -696,6 +696,8 @@ static bool sc16is7xx_port_irq(struct sc
 			rxlen = sc16is7xx_port_read(port, SC16IS7XX_RXLVL_REG);
 			if (rxlen)
 				sc16is7xx_handle_rx(port, rxlen, iir);
+			else
+				return false;
 			break;
 		case SC16IS7XX_IIR_THRI_SRC:
 			sc16is7xx_handle_tx(port);