From 4160ac6de172fef55df4ed6d0a0f1dfaab5ff795 Mon Sep 17 00:00:00 2001
From: Matthias von Faber <matthias.vonfaber@aox-tech.de>
Date: Mon, 11 Oct 2021 14:32:28 +0200
Subject: [PATCH 4/4] drivers/tty: further increase tty_buffer_worker priority
Patch-mainline: Never, downstream fix.
References: jsc#EB-390, bsc#1191701, jsc#EB-310
Derivative of https://www.spinics.net/lists/linux-serial/msg17782.html
The BMW system required (ref.: jsc#EB-310) further
increase of TTY priority to reduce latency.
Elektrobit is responsible for this patch.
Signed-off-by: Steven Walter <stevenrwalter@gmail.com>
Signed-off-by: Matthias von Faber <matthias.vonfaber@aox-tech.de>
Signed-off-by: Bogdan Lezhepekov <blezhepekov@suse.de>
Signed-off-by: Peter Kunath <Peter.Kunath@elektrobit.com>
Signed-off-by: Muhammad Faisal <Muhammad.Faisal@elektrobit.com>
---
drivers/tty/tty_buffer.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/tty/tty_buffer.c b/drivers/tty/tty_buffer.c
index 14056096d4d33..91b2f3a90994f 100644
--- a/drivers/tty/tty_buffer.c
+++ b/drivers/tty/tty_buffer.c
@@ -569,7 +569,7 @@ bool tty_buffer_queue_work(struct tty_port *port)
void tty_buffer_init_kthread(void)
{
- struct sched_param param = { .sched_priority = 1 };
+ struct sched_param param = { .sched_priority = MAX_USER_RT_PRIO / 2 };
struct task_struct *kworker_task;
kworker_task = kthread_run(kthread_worker_fn, &tty_buffer_worker, "tty");
--
2.33.1