[PATCH net v2] net: dsa: mv88e6xxx: fix handling of upper half of STATS_TYPE_PORT

[PATCH net v2] net: dsa: mv88e6xxx: fix handling of upper half of STATS_TYPE_PORT

[Rasmus Villemoes]

Currently, the upper half of a 4-byte STATS_TYPE_PORT statistic ends
up in bits 47:32 of the return value, instead of bits 31:16 as they
should.

Fixes: 6e46e2d821bb ("net: dsa: mv88e6xxx: Fix u64 statistics")
Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
---
v2: include Fixes tag, use proper subject prefix.

 drivers/net/dsa/mv88e6xxx/chip.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/dsa/mv88e6xxx/chip.c b/drivers/net/dsa/mv88e6xxx/chip.c
index 370434bdbdab..317553d2cb21 100644
--- a/drivers/net/dsa/mv88e6xxx/chip.c
+++ b/drivers/net/dsa/mv88e6xxx/chip.c
@@ -785,7 +785,7 @@ static uint64_t _mv88e6xxx_get_ethtool_stat(struct mv88e6xxx_chip *chip,
 			err = mv88e6xxx_port_read(chip, port, s->reg + 1, &reg);
 			if (err)
 				return U64_MAX;
-			high = reg;
+			low |= ((u32)reg) << 16;
 		}
 		break;
 	case STATS_TYPE_BANK1:
-- 
2.20.1

Re: [PATCH net v2] net: dsa: mv88e6xxx: fix handling of upper half of STATS_TYPE_PORT

[Vivien Didelot]

Hi Rasmus,

On Wed, 29 May 2019 07:02:11 +0000, Rasmus Villemoes <rasmus.villemoes@prevas.dk> wrote:
> Currently, the upper half of a 4-byte STATS_TYPE_PORT statistic ends
> up in bits 47:32 of the return value, instead of bits 31:16 as they
> should.
> 
> Fixes: 6e46e2d821bb ("net: dsa: mv88e6xxx: Fix u64 statistics")
> Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>

Correct, this 4-byte stat must be stored in the lower half of the
8-byte returned value:

Reviewed-by: Vivien Didelot <vivien.didelot@gmail.com>

Re: [PATCH net v2] net: dsa: mv88e6xxx: fix handling of upper half of STATS_TYPE_PORT

[David Miller]

From: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
Date: Wed, 29 May 2019 07:02:11 +0000

> Currently, the upper half of a 4-byte STATS_TYPE_PORT statistic ends
> up in bits 47:32 of the return value, instead of bits 31:16 as they
> should.
> 
> Fixes: 6e46e2d821bb ("net: dsa: mv88e6xxx: Fix u64 statistics")
> Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
> ---
> v2: include Fixes tag, use proper subject prefix.

Applied and queued up for -stable, thanks.