Subject: [PATCH AUTOSEL 4.20 203/304] bnxt_en: Disable MSIX before re-reserving NQs/CMPL rings.

From: Sasha Levin <[email-masked]>
Date: Mon, 28 Jan 2019 10:42:00 -0500

From: Michael Chan <[email-masked]>

[ Upstream commit 36d65be9a88052cdfc8524eb591baf0e6c878408 ]

When bringing up a device, the code checks to see if the number of
MSIX has changed.  pci_disable_msix() should be called first before
changing the number of reserved NQs/CMPL rings.  This ensures that
the MSIX vectors associated with the NQs/CMPL rings are still
properly mapped when pci_disable_msix() masks the vectors.

This patch will prevent errors when RDMA support is added for the new
57500 chips.  When the RDMA driver shuts down, the number of NQs is
decreased and we must use the new sequence to prevent MSIX errors.

Signed-off-by: Michael Chan <[email-masked]>
Signed-off-by: David S. Miller <[email-masked]>
Signed-off-by: Sasha Levin <[email-masked]>
---
 drivers/net/ethernet/broadcom/bnxt/bnxt.c | 19 +++++++++++--------
 1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index 5d21c14853ac..50a4c3ddf977 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -7203,23 +7203,26 @@ static void bnxt_clear_int_mode(struct bnxt *bp)
 int bnxt_reserve_rings(struct bnxt *bp)
 {
 	int tcs = netdev_get_num_tc(bp->dev);
+	bool reinit_irq = false;
 	int rc;
 
 	if (!bnxt_need_reserve_rings(bp))
 		return 0;
 
-	rc = __bnxt_reserve_rings(bp);
-	if (rc) {
-		netdev_err(bp->dev, "ring reservation failure rc: %d\n", rc);
-		return rc;
-	}
 	if (BNXT_NEW_RM(bp) && (bnxt_get_num_msix(bp) != bp->total_irqs)) {
 		bnxt_ulp_irq_stop(bp);
 		bnxt_clear_int_mode(bp);
-		rc = bnxt_init_int_mode(bp);
+		reinit_irq = true;
+	}
+	rc = __bnxt_reserve_rings(bp);
+	if (reinit_irq) {
+		if (!rc)
+			rc = bnxt_init_int_mode(bp);
 		bnxt_ulp_irq_restart(bp, rc);
-		if (rc)
-			return rc;
+	}
+	if (rc) {
+		netdev_err(bp->dev, "ring reservation/IRQ init failure rc: %d\n", rc);
+		return rc;
 	}
 	if (tcs && (bp->tx_nr_rings_per_tc * tcs != bp->tx_nr_rings)) {
 		netdev_err(bp->dev, "tx ring reservation failure\n");
-- 
2.19.1