[net PATCH V2 4/4] octeonxt2-pf: Fix backpressure config for multiple PFC priorities to work simultaneously

[Suman Ghosh <sumang@marvell.com>]

MAC (CGX or RPM) asserts backpressure at TL3 or TL2 node of the egress
hierarchical scheduler tree depending on link level config done. If
there are multiple PFC priorities enabled at a time and for all such
flows to backoff, each priority will have to assert backpressure at
different TL3/TL2 scheduler nodes and these flows will need to submit
egress pkts to these nodes.

Current PFC configuration has an issue where in only one backpressure
scheduler node is being allocated which is resulting in only one PFC
priority to work. This patch fixes this issue.

Fixes: 99c969a83d82 ("octeontx2-pf: Add egress PFC support")
Signed-off-by: Suman Ghosh <sumang@marvell.com>
---
 .../net/ethernet/marvell/octeontx2/nic/otx2_dcbnl.c    | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_dcbnl.c b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_dcbnl.c
index c75435bab411..048ee015c085 100644
--- a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_dcbnl.c
+++ b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_dcbnl.c
@@ -70,7 +70,7 @@ static int otx2_pfc_txschq_alloc_one(struct otx2_nic *pfvf, u8 prio)
 	 * link config level. These rest of the scheduler can be
 	 * same as hw.txschq_list.
 	 */
-	for (lvl = 0; lvl < pfvf->hw.txschq_link_cfg_lvl; lvl++)
+	for (lvl = 0; lvl <= pfvf->hw.txschq_link_cfg_lvl; lvl++)
 		req->schq[lvl] = 1;
 
 	rc = otx2_sync_mbox_msg(&pfvf->mbox);
@@ -83,7 +83,7 @@ static int otx2_pfc_txschq_alloc_one(struct otx2_nic *pfvf, u8 prio)
 		return PTR_ERR(rsp);
 
 	/* Setup transmit scheduler list */
-	for (lvl = 0; lvl < pfvf->hw.txschq_link_cfg_lvl; lvl++) {
+	for (lvl = 0; lvl <= pfvf->hw.txschq_link_cfg_lvl; lvl++) {
 		if (!rsp->schq[lvl])
 			return -ENOSPC;
 
@@ -128,7 +128,7 @@ static int otx2_pfc_txschq_stop_one(struct otx2_nic *pfvf, u8 prio)
 	int lvl;
 
 	/* free PFC TLx nodes */
-	for (lvl = 0; lvl < pfvf->hw.txschq_link_cfg_lvl; lvl++)
+	for (lvl = 0; lvl <= pfvf->hw.txschq_link_cfg_lvl; lvl++)
 		otx2_txschq_free_one(pfvf, lvl,
 				     pfvf->pfc_schq_list[lvl][prio]);
 
@@ -400,9 +400,11 @@ static int otx2_dcbnl_ieee_setpfc(struct net_device *dev, struct ieee_pfc *pfc)
 {
 	struct otx2_nic *pfvf = netdev_priv(dev);
 	bool if_up = netif_running(dev);
+	u8 prev_pfc_en;
 	int err;
 
 	/* Save PFC configuration to interface */
+	prev_pfc_en = pfvf->pfc_en;
 	pfvf->pfc_en = pfc->pfc_en;
 
 	if (pfvf->hw.tx_queues >= NIX_PF_PFC_PRIO_MAX)
@@ -421,7 +423,9 @@ static int otx2_dcbnl_ieee_setpfc(struct net_device *dev, struct ieee_pfc *pfc)
 		return err;
 
 	if (if_up) {
+		pfvf->pfc_en = prev_pfc_en;
 		otx2_stop(dev);
+		pfvf->pfc_en = pfc->pfc_en;
 		otx2_open(dev);
 	}
 
-- 
2.25.1