[PATCH 4.9 07/42] MIPS: lantiq: Fix bitfield masking

[Greg Kroah-Hartman]

[ 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@xxxxxxxxx>
Signed-off-by: Paul Burton <paul.burton@xxxxxxxx>
Cc: hauke@xxxxxxxxxx
Cc: john@xxxxxxxxxxx
Cc: linux-mips@xxxxxxxxxxxxxxx
Cc: openwrt-devel@xxxxxxxxxxxxxxxxx
Cc: pakahmar@xxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 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 8ac0e5994ed29..7c6f75c2aa4df 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