RDMA/nes: Clear stall bit before destroying NIC QP

Clear the stall bit to drop any incoming packets while destroying NIC
QP.  This will prevent a chip resource leak.

Signed-off-by: Chien Tung <chien.tin.tung@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

drivers/infiniband/hw/nes/nes_hw.c

@@ -1899,9 +1899,14 @@ void nes_destroy_nic_qp(struct nes_vnic *nesvnic)
 	u16  wqe_fragment_index;
 	u64 wqe_frag;
 	u32 cqp_head;
+	u32 wqm_cfg0;
 	unsigned long flags;
 	int ret;
 
+	/* clear wqe stall before destroying NIC QP */
+	wqm_cfg0 = nes_read_indexed(nesdev, NES_IDX_WQM_CONFIG0);
+	nes_write_indexed(nesdev, NES_IDX_WQM_CONFIG0, wqm_cfg0 & 0xFFFF7FFF);
+
 	/* Free remaining NIC receive buffers */
 	while (nesvnic->nic.rq_head != nesvnic->nic.rq_tail) {
 		nic_rqe   = &nesvnic->nic.rq_vbase[nesvnic->nic.rq_tail];
@@ -2020,6 +2025,9 @@ void nes_destroy_nic_qp(struct nes_vnic *nesvnic)
 
 	pci_free_consistent(nesdev->pcidev, nesvnic->nic_mem_size, nesvnic->nic_vbase,
 			nesvnic->nic_pbase);
+
+	/* restore old wqm_cfg0 value */
+	nes_write_indexed(nesdev, NES_IDX_WQM_CONFIG0, wqm_cfg0);
 }
 
 /**

drivers/infiniband/hw/nes/nes_hw.h

@@ -160,6 +160,7 @@ enum indexed_regs {
 	NES_IDX_ENDNODE0_NSTAT_TX_OCTETS_HI = 0x7004,
 	NES_IDX_ENDNODE0_NSTAT_TX_FRAMES_LO = 0x7008,
 	NES_IDX_ENDNODE0_NSTAT_TX_FRAMES_HI = 0x700c,
+	NES_IDX_WQM_CONFIG0 = 0x5000,
 	NES_IDX_WQM_CONFIG1 = 0x5004,
 	NES_IDX_CM_CONFIG = 0x5100,
 	NES_IDX_NIC_LOGPORT_TO_PHYPORT = 0x6000,