0001-allwinner-a64-clock.patch

From 5fcb4e57eeaa4d670ef4acf5818c6fe16aa0d3d0 Mon Sep 17 00:00:00 2001
From: Ryan Sundberg <ryan@arctype.co>
Date: Fri, 14 Jun 2019 07:49:06 +0000
Subject: [PATCH] Revert to original method to read stable timer registers on
 A64

https://github.com/longsleep/linux-pine64/commit/a08f5219d240ae0edf93d090ff1fda0a82a6cb3a
---
 drivers/clocksource/arm_arch_timer.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
index aa4ec53281cea..067a04055df68 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -335,16 +335,17 @@ static u64 notrace arm64_1188873_read_cntvct_el0(void)
  * number of CPU cycles in 3 consecutive 24 MHz counter periods.
  */
 #define __sun50i_a64_read_reg(reg) ({					\
-	u64 _val;							\
-	int _retries = 150;						\
+	u64 _old, _new;							\
+	int _retries = 200;						\
 									\
 	do {								\
-		_val = read_sysreg(reg);				\
+		_old = read_sysreg(reg);				\
+		_new = read_sysreg(reg);				\
 		_retries--;						\
-	} while (((_val + 1) & GENMASK(9, 0)) <= 1 && _retries);	\
+	} while (unlikely(_old != _new) && _retries);			\
 									\
 	WARN_ON_ONCE(!_retries);					\
-	_val;								\
+	_new;								\
 })
 
 static u64 notrace sun50i_a64_read_cntpct_el0(void)