Commit c08c5965 authored by Edwin Peer's avatar Edwin Peer Committed by David S. Miller
Browse files

bnxt_en: reject ETS settings that will starve a TC 



ETS proportions are presented to HWRM_QUEUE_COS2BW_CFG as minimum
bandwidth constraints. Thus, zero is a legal value for a given TC.
However, if all the other TCs sum up to 100%, then at least one
hardware queue will starve, resulting in guaranteed TX timeouts.
Reject such nonsensical configurations.

Reviewed-by: default avatarPavan Chebbi <pavan.chebbi@broadcom.com>
Signed-off-by: default avatarEdwin Peer <edwin.peer@broadcom.com>
Signed-off-by: default avatarMichael Chan <michael.chan@broadcom.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent c81cfb62

drivers/net/ethernet/broadcom/bnxt/bnxt_dcb.c

+9 −1
Original line number Diff line number Diff line
@@ -433,6 +433,7 @@ static int bnxt_hwrm_queue_dscp2pri_cfg(struct bnxt *bp, struct dcb_app *app, 
static int bnxt_ets_validate(struct bnxt *bp, struct ieee_ets *ets, u8 *tc)

{

	int total_ets_bw = 0;

	bool zero = false;

	u8 max_tc = 0;

	int i;
@@ -453,13 +454,20 @@ static int bnxt_ets_validate(struct bnxt *bp, struct ieee_ets *ets, u8 *tc) 
			break;

		case IEEE_8021QAZ_TSA_ETS:

			total_ets_bw += ets->tc_tx_bw[i];

			zero = zero || !ets->tc_tx_bw[i];

			break;

		default:

			return -ENOTSUPP;

		}

	}

	if (total_ets_bw > 100)

	if (total_ets_bw > 100) {

		netdev_warn(bp->dev, "rejecting ETS config exceeding available bandwidth\n");

		return -EINVAL;

	}

	if (zero && total_ets_bw == 100) {

		netdev_warn(bp->dev, "rejecting ETS config starving a TC\n");

		return -EINVAL;

	}



	if (max_tc >= bp->max_tc)

		*tc = bp->max_tc;