[PATCH 4.4 049/146] ARCv2: LLSC: software backoff is NOT needed starting HS2.1c

From: Greg Kroah-Hartman
Date: Mon Jul 25 2016 - 16:59:41 EST


4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Vineet Gupta <vgupta@xxxxxxxxxxxx>

commit b31ac42697bef4a3aa5d0aa42375a55657f57174 upstream.

Signed-off-by: Vineet Gupta <vgupta@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
arch/arc/Kconfig | 2 +-
arch/arc/kernel/setup.c | 5 -----
2 files changed, 1 insertion(+), 6 deletions(-)

--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -387,7 +387,7 @@ config ARC_HAS_LLSC

config ARC_STAR_9000923308
bool "Workaround for llock/scond livelock"
- default y
+ default n
depends on ISA_ARCV2 && SMP && ARC_HAS_LLSC

config ARC_HAS_SWAPE
--- a/arch/arc/kernel/setup.c
+++ b/arch/arc/kernel/setup.c
@@ -332,11 +332,6 @@ static void arc_chk_core_config(void)
pr_warn("CONFIG_ARC_FPU_SAVE_RESTORE needed for working apps\n");
else if (!cpu->extn.fpu_dp && fpu_enabled)
panic("FPU non-existent, disable CONFIG_ARC_FPU_SAVE_RESTORE\n");
-
- if (is_isa_arcv2() && IS_ENABLED(CONFIG_SMP) && cpu->isa.atomic &&
- IS_ENABLED(CONFIG_ARC_HAS_LLSC) &&
- !IS_ENABLED(CONFIG_ARC_STAR_9000923308))
- panic("llock/scond livelock workaround missing\n");
}

/*