[PATCH] arc: Keep D$ enabled to work-around incomplete SLC flushing

From: Alexey Brodkin
Date: Fri Mar 17 2017 - 09:00:45 EST


As reported in STAR 9001165532 if D$ is disabled SLC is not flushed
correctly which leads to loses of some data that were set before the flush.
That causes unexpected behavior after the flush.

For now just keep D$ enabled, only flush-invalidate it before IOC setup.

Signed-off-by: Alexey Brodkin <abrodkin@xxxxxxxxxxxx>
---
arch/arc/mm/cache.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arc/mm/cache.c b/arch/arc/mm/cache.c
index d408fa21a07c..e0e83543e777 100644
--- a/arch/arc/mm/cache.c
+++ b/arch/arc/mm/cache.c
@@ -997,8 +997,8 @@ noinline void __init arc_ioc_setup(void)
{
unsigned int ap_sz;

- /* Flush + invalidate + disable L1 dcache */
- __dc_disable();
+ /* Flush + invalidate L1 dcache */
+ __dc_entire_op(OP_FLUSH_N_INV);

/* Flush + invalidate SLC */
if (read_aux_reg(ARC_REG_SLC_BCR))
--
2.7.4