bnxt_en: Fix possible BUG() condition when calling pci_disable_msix().

When making configuration changes, the driver calls bnxt_close_nic()
and then bnxt_open_nic() for the changes to take effect.  A parameter
irq_re_init is passed to the call sequence to indicate if IRQ
should be re-initialized.  This irq_re_init parameter needs to
be included in the bnxt_reserve_rings() call.  bnxt_reserve_rings()
can only call pci_disable_msix() if the irq_re_init parameter is
true, otherwise it may hit BUG() because some IRQs may not have been
freed yet.

Fixes: 41e8d798 ("bnxt_en: Modify the ring reservation functions for 57500 series chips.")
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -7618,22 +7618,23 @@ static void bnxt_clear_int_mode(struct bnxt *bp)
 	bp->flags &= ~BNXT_FLAG_USING_MSIX;
 }
 
-int bnxt_reserve_rings(struct bnxt *bp)
+int bnxt_reserve_rings(struct bnxt *bp, bool irq_re_init)
 {
 	int tcs = netdev_get_num_tc(bp->dev);
-	bool reinit_irq = false;
+	bool irq_cleared = false;
 	int rc;
 
 	if (!bnxt_need_reserve_rings(bp))
 		return 0;
 
-	if (BNXT_NEW_RM(bp) && (bnxt_get_num_msix(bp) != bp->total_irqs)) {
+	if (irq_re_init && BNXT_NEW_RM(bp) &&
+	    bnxt_get_num_msix(bp) != bp->total_irqs) {
 		bnxt_ulp_irq_stop(bp);
 		bnxt_clear_int_mode(bp);
-		reinit_irq = true;
+		irq_cleared = true;
 	}
 	rc = __bnxt_reserve_rings(bp);
-	if (reinit_irq) {
+	if (irq_cleared) {
 		if (!rc)
 			rc = bnxt_init_int_mode(bp);
 		bnxt_ulp_irq_restart(bp, rc);
@@ -8532,7 +8533,7 @@ static int __bnxt_open_nic(struct bnxt *bp, bool irq_re_init, bool link_re_init)
 			return rc;
 		}
 	}
-	rc = bnxt_reserve_rings(bp);
+	rc = bnxt_reserve_rings(bp, irq_re_init);
 	if (rc)
 		return rc;
 	if ((bp->flags & BNXT_FLAG_RFS) &&

drivers/net/ethernet/broadcom/bnxt/bnxt.h

@@ -1790,7 +1790,7 @@ unsigned int bnxt_get_avail_stat_ctxs_for_en(struct bnxt *bp);
 unsigned int bnxt_get_max_func_cp_rings(struct bnxt *bp);
 unsigned int bnxt_get_avail_cp_rings_for_en(struct bnxt *bp);
 int bnxt_get_avail_msix(struct bnxt *bp, int num);
-int bnxt_reserve_rings(struct bnxt *bp);
+int bnxt_reserve_rings(struct bnxt *bp, bool irq_re_init);
 void bnxt_tx_disable(struct bnxt *bp);
 void bnxt_tx_enable(struct bnxt *bp);
 int bnxt_hwrm_set_pause(struct bnxt *);

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

@@ -831,7 +831,7 @@ static int bnxt_set_channels(struct net_device *dev,
 			 */
 		}
 	} else {
-		rc = bnxt_reserve_rings(bp);
+		rc = bnxt_reserve_rings(bp, true);
 	}
 
 	return rc;

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

@@ -147,7 +147,7 @@ static int bnxt_req_msix_vecs(struct bnxt_en_dev *edev, int ulp_id,
 			bnxt_close_nic(bp, true, false);
 			rc = bnxt_open_nic(bp, true, false);
 		} else {
-			rc = bnxt_reserve_rings(bp);
+			rc = bnxt_reserve_rings(bp, true);
 		}
 	}
 	if (rc) {