[PATCH AUTOSEL 4.9 07/30] MIPS: lantiq: Fix bitfield masking

[Sasha Levin <sashal@kernel.org>]

From: Petr Cvek <petrcvekcz@gmail.com>

[ Upstream commit ba1bc0fcdeaf3bf583c1517bd2e3e29cf223c969 ]

The modification of EXIN register doesn't clean the bitfield before
the writing of a new value. After a few modifications the bitfield would
accumulate only '1's.

Signed-off-by: Petr Cvek <petrcvekcz@gmail.com>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: hauke@hauke-m.de
Cc: john@phrozen.org
Cc: linux-mips@vger.kernel.org
Cc: openwrt-devel@lists.openwrt.org
Cc: pakahmar@hotmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/mips/lantiq/irq.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/mips/lantiq/irq.c b/arch/mips/lantiq/irq.c
index 8ac0e5994ed2..7c6f75c2aa4d 100644
--- a/arch/mips/lantiq/irq.c
+++ b/arch/mips/lantiq/irq.c
@@ -160,8 +160,9 @@ static int ltq_eiu_settype(struct irq_data *d, unsigned int type)
 			if (edge)
 				irq_set_handler(d->hwirq, handle_edge_irq);
 
-			ltq_eiu_w32(ltq_eiu_r32(LTQ_EIU_EXIN_C) |
-				(val << (i * 4)), LTQ_EIU_EXIN_C);
+			ltq_eiu_w32((ltq_eiu_r32(LTQ_EIU_EXIN_C) &
+				    (~(7 << (i * 4)))) | (val << (i * 4)),
+				    LTQ_EIU_EXIN_C);
 		}
 	}
 
-- 
2.20.1