[PATCH] net/ice: fix statistics read error

[PATCH] net/ice: fix statistics read error

[Zhichao Zeng]

The statistics contain 40 bits. The lower 32 bits are read first, followed
by the upper 8 bits.

In some cases, after reading the lower 32 bits, a carry occurs from the
lower bits, which causes the final statistics to be incorrect.

This commit fixes this issue.

Fixes: a37bde56314d ("net/ice: support statistics")
Cc: stable@dpdk.org

Signed-off-by: Zhichao Zeng <zhichaox.zeng@intel.com>
---
 drivers/net/intel/ice/ice_ethdev.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/drivers/net/intel/ice/ice_ethdev.c b/drivers/net/intel/ice/ice_ethdev.c
index 513777e372..be08be0826 100644
--- a/drivers/net/intel/ice/ice_ethdev.c
+++ b/drivers/net/intel/ice/ice_ethdev.c
@@ -6036,10 +6036,19 @@ ice_stat_update_40(struct ice_hw *hw,
 		   uint64_t *stat)
 {
 	uint64_t new_data;
+	uint32_t lo, hi, lo2;
 
-	new_data = (uint64_t)ICE_READ_REG(hw, loreg);
-	new_data |= (uint64_t)(ICE_READ_REG(hw, hireg) & ICE_8_BIT_MASK) <<
-		    ICE_32_BIT_WIDTH;
+	lo = ICE_READ_REG(hw, loreg);
+	hi = ICE_READ_REG(hw, hireg);
+	lo2 = ICE_READ_REG(hw, loreg);
+
+	if (lo2 < lo) {
+		lo = ICE_READ_REG(hw, loreg);
+		hi = ICE_READ_REG(hw, hireg);
+	}
+
+	new_data = (uint64_t)lo;
+	new_data |= (uint64_t)(hi & ICE_8_BIT_MASK) << ICE_32_BIT_WIDTH;
 
 	if (!offset_loaded)
 		*offset = new_data;
-- 
2.34.1