[PATCH net 2/9] bnxt_en: reject ETS settings that will starve a TC
From: Michael Chan <michael.chan@broadcom.com>
Date: 2021-07-18 19:36:53
Subsystem:
broadcom bnxt_en 50 gigabit ethernet driver, networking drivers, the rest · Maintainers:
Michael Chan, Pavan Chebbi, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
From: Edwin Peer <redacted> 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: Pavan Chebbi <pavan.chebbi@broadcom.com> Signed-off-by: Edwin Peer <redacted> Signed-off-by: Michael Chan <michael.chan@broadcom.com> --- drivers/net/ethernet/broadcom/bnxt/bnxt_dcb.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_dcb.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_dcb.c
index 8e90224c43a2..8a68df4d9e59 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_dcb.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_dcb.c@@ -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;
--
2.18.1
Attachments
- smime.p7s [application/pkcs7-signature] 4209 bytes