From 17c5bda2a91cf902e0897bd8178f96aa5e3adf78 Mon Sep 17 00:00:00 2001
From: Vitaly Andrianov <vitalya@ti.com>
Date: Wed, 8 Jul 2015 11:40:14 -0400
Subject: [PATCH] keystone2: add wfi in to the core_spin loop
When core A turning of core B, via tetris DPSC it places the core
B DPSC into transitional state. The core B has to execute wfi instruction
to move its DPSC to the OFF state. This patch add such instruction.
Signed-off-by: Vitaly Andrianov <vitalya@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
---
arch/arm/mach-keystone/cmd_mon.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/arch/arm/mach-keystone/cmd_mon.c b/arch/arm/mach-keystone/cmd_mon.c
index f9f58a37df..73ceb83072 100644
--- a/arch/arm/mach-keystone/cmd_mon.c
+++ b/arch/arm/mach-keystone/cmd_mon.c
@@ -55,8 +55,13 @@ U_BOOT_CMD(mon_install, 2, 0, do_mon_install,
static void core_spin(void)
{
- while (1)
- ; /* forever */;
+ while (1) {
+ asm volatile (
+ "dsb\n"
+ "isb\n"
+ "wfi\n"
+ );
+ }
}
int mon_power_on(int core_id, void *ep)
--
2.39.5