[PATCH 3.16 107/233] bnx2x: Fix Multi-Cos

From: Ben Hutchings
Date: Sat Sep 09 2017 - 19:30:18 EST


3.16.48-rc1 review patch. If anyone has any objections, please let me know.

------------------

From: "Mintz, Yuval" <Yuval.Mintz@xxxxxxxxxx>

commit 3968d38917eb9bd0cd391265f6c9c538d9b33ffa upstream.

Apparently multi-cos isn't working for bnx2x quite some time -
driver implements ndo_select_queue() to allow queue-selection
for FCoE, but the regular L2 flow would cause it to modulo the
fallback's result by the number of queues.
The fallback would return a queue matching the needed tc
[via __skb_tx_hash()], but since the modulo is by the number of TSS
queues where number of TCs is not accounted, transmission would always
be done by a queue configured into using TC0.

Fixes: ada7c19e6d27 ("bnx2x: use XPS if possible for bnx2x_select_queue instead of pure hash")
Signed-off-by: Yuval Mintz <Yuval.Mintz@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c
+++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c
@@ -1914,7 +1914,7 @@ u16 bnx2x_select_queue(struct net_device
}

/* select a non-FCoE queue */
- return fallback(dev, skb) % BNX2X_NUM_ETH_QUEUES(bp);
+ return fallback(dev, skb) % (BNX2X_NUM_ETH_QUEUES(bp) * bp->max_cos);
}

void bnx2x_set_num_queues(struct bnx2x *bp)