[PATCH 5.15 084/132] ice: fix possible under reporting of ethtool Tx and Rx statistics

Greg Kroah-Hartman
2022-05-23T17:35:24Z

From: Paul Greenwalt <paul.greenwalt@intel.com>

[ Upstream commit 31b6298fd8e29effe9ed6b77351ac5969be56ce0 ]

The hardware statistics counters are not cleared during resets so the
drivers first access is to initialize the baseline and then subsequent
reads are for reporting the counters. The statistics counters are read
during the watchdog subtask when the interface is up. If the baseline
is not initialized before the interface is up, then there can be a brief
window in which some traffic can be transmitted/received before the
initial baseline reading takes place.

Directly initialize ethtool statistics in driver open so the baseline will
be initialized when the interface is up, and any dropped packets
incremented before the interface is up won't be reported.

Fixes: 28dc1b86f8ea9 ("ice: ignore dropped packets during init")
Signed-off-by: Paul Greenwalt <paul.greenwalt@intel.com>
Tested-by: Gurucharan <gurucharanx.g@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/intel/ice/ice_main.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_main.c b/drivers/net/ethernet/intel/ice/ice_main.c
index 27b5c75ce386..188abf36a5b2 100644
--- a/drivers/net/ethernet/intel/ice/ice_main.c
+++ b/drivers/net/ethernet/intel/ice/ice_main.c
@@ -5656,9 +5656,10 @@ static int ice_up_complete(struct ice_vsi *vsi)
netif_carrier_on(vsi->netdev);
}

- /* clear this now, and the first stats read will be used as baseline */
- vsi->stat_offsets_loaded = false;
-
+ /* Perform an initial read of the statistics registers now to
+ * set the baseline so counters are ready when interface is up
+ */
+ ice_update_eth_stats(vsi);
ice_service_task_schedule(pf);

return 0;
--
2.35.1