[PATCH 4.14 07/53] MIPS: lantiq: Fix bitfield masking

From: Greg Kroah-Hartman
Date: Mon Aug 05 2019 - 09:14:37 EST


[ 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 c4ef1c31e0c4f..37caeadb2964c 100644
--- a/arch/mips/lantiq/irq.c
+++ b/arch/mips/lantiq/irq.c
@@ -156,8 +156,9 @@ 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