From: Michael Chan michael.chan@broadcom.com
[ Upstream commit fa97f303fa4cf8469fd3d1ef29da69c0a3f6ddc8 ]
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 vasundhara-v.volam@broadcom.com Reviewed-by: Pavan Chebbi pavan.chebbi@broadcom.com Reviewed-by: Edwin Peer edwin.peer@broadcom.com Signed-off-by: Michael Chan michael.chan@broadcom.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/ethernet/broadcom/bnxt/bnxt.c | 1 + 1 file changed, 1 insertion(+)
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c @@ -7617,6 +7617,7 @@ static void bnxt_add_one_ctr(u64 hw, u64 { u64 sw_tmp;
+ hw &= mask; sw_tmp = (*sw & ~mask) | hw; if (hw < (*sw & mask)) sw_tmp += mask + 1;