linux/debian/patches-rt/0167-rt-Improve-the-serial-console-PASS_LIMIT.patch

From d3da9ac80ca53a41300046b8235d29328fbc0679 Mon Sep 17 00:00:00 2001
Message-Id: <d3da9ac80ca53a41300046b8235d29328fbc0679.1596234183.git.zanussi@kernel.org>
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From: Ingo Molnar <mingo@elte.hu>
Date: Wed, 14 Dec 2011 13:05:54 +0100
Subject: [PATCH 167/329] rt: Improve the serial console PASS_LIMIT
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Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patches-4.19.135-rt60.tar.xz

Beyond the warning:

 drivers/tty/serial/8250/8250.c:1613:6: warning: unused variable ‘pass_counter’ [-Wunused-variable]

the solution of just looping infinitely was ugly - up it to 1 million to
give it a chance to continue in some really ugly situation.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 drivers/tty/serial/8250/8250_core.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c
index e1a5887b6d91..129c9383f96c 100644
--- a/drivers/tty/serial/8250/8250_core.c
+++ b/drivers/tty/serial/8250/8250_core.c
@@ -54,7 +54,16 @@ static struct uart_driver serial8250_reg;
 
 static unsigned int skip_txen_test; /* force skip of txen test at init time */
 
-#define PASS_LIMIT	512
+/*
+ * On -rt we can have a more delays, and legitimately
+ * so - so don't drop work spuriously and spam the
+ * syslog:
+ */
+#ifdef CONFIG_PREEMPT_RT_FULL
+# define PASS_LIMIT	1000000
+#else
+# define PASS_LIMIT	512
+#endif
 
 #include <asm/serial.h>
 /*
-- 
2.17.1