From fa97f303fa4cf8469fd3d1ef29da69c0a3f6ddc8 Mon Sep 17 00:00:00 2001 From: Michael Chan Date: Sun, 15 Nov 2020 19:27:51 -0500 Subject: [PATCH] bnxt_en: Fix counter overflow logic. bnxt_add_one_ctr() adds a hardware counter to a software counter and adjusts for the hardware counter wraparound against the mask. The logic assumes that the hardware counter is always smaller than or equal to the mask. This assumption is mostly correct. But in some cases if the firmware is older and does not provide the accurate mask, the driver can use a mask that is smaller than the actual hardware mask. This can cause some extra carry bits to be added to the software counter, resulting in counters that far exceed the actual value. Fix it by masking the hardware counter with the mask passed into bnxt_add_one_ctr(). Fixes: fea6b3335527 ("bnxt_en: Accumulate all counters.") Reviewed-by: Vasundhara Volam Reviewed-by: Pavan Chebbi Reviewed-by: Edwin Peer Signed-off-by: Michael Chan Signed-off-by: Jakub Kicinski --- drivers/net/ethernet/broadcom/bnxt/bnxt.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c index 448e1ba762ee..7c21aaa8b9af 100644 --- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c @@ -7758,6 +7758,7 @@ static void bnxt_add_one_ctr(u64 hw, u64 *sw, u64 mask) { u64 sw_tmp; + hw &= mask; sw_tmp = (*sw & ~mask) | hw; if (hw < (*sw & mask)) sw_tmp += mask + 1; -- 2.25.1