[PATCH 4.4 287/312] net: mvneta: fix trivial cut-off issue in mvneta_ethtool_update_stats

[Greg Kroah-Hartman]

From: Jisheng Zhang <jszhang@xxxxxxxxxxx>

commit 2c832293e09be2f998ea916650927c8ccd5b4b3b upstream.

When s->type is T_REG_64, the high 32bits are lost in val. This patch
fixes this trivial issue.

Signed-off-by: Jisheng Zhang <jszhang@xxxxxxxxxxx>
Fixes: 9b0cdefa4cd5 ("net: mvneta: add ethtool statistics")
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/net/ethernet/marvell/mvneta.c |    9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

--- a/drivers/net/ethernet/marvell/mvneta.c
+++ b/drivers/net/ethernet/marvell/mvneta.c
@@ -3058,26 +3058,25 @@ static void mvneta_ethtool_update_stats(
 	const struct mvneta_statistic *s;
 	void __iomem *base = pp->base;
 	u32 high, low, val;
+	u64 val64;
 	int i;
 
 	for (i = 0, s = mvneta_statistics;
 	     s < mvneta_statistics + ARRAY_SIZE(mvneta_statistics);
 	     s++, i++) {
-		val = 0;
-
 		switch (s->type) {
 		case T_REG_32:
 			val = readl_relaxed(base + s->offset);
+			pp->ethtool_stats[i] += val;
 			break;
 		case T_REG_64:
 			/* Docs say to read low 32-bit then high */
 			low = readl_relaxed(base + s->offset);
 			high = readl_relaxed(base + s->offset + 4);
-			val = (u64)high << 32 | low;
+			val64 = (u64)high << 32 | low;
+			pp->ethtool_stats[i] += val64;
 			break;
 		}
-
-		pp->ethtool_stats[i] += val;
 	}
 }