[PATCH v4] raw/ntb: clear all valid DB bits when DB init

[Junfeng Guo <junfeng.guo@intel.com>]

Before registering the doorbell interrupt handler callback function,
all the valid doorbell bits within the NTB private data struct should
be cleared to avoid the confusion of the handshake timing sequence
diagram when setting up the NTB connection in back-to-back mode.

Fixes: 62012a76811e ("raw/ntb: add handshake process")
Cc: stable@dpdk.org

v2: fix typo
v3: fix coding style issue
v4: add ops check before calling it

Signed-off-by: Junfeng Guo <junfeng.guo@intel.com>
---
 drivers/raw/ntb/ntb.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/raw/ntb/ntb.c b/drivers/raw/ntb/ntb.c
index 46ac02e5ab..f5e773c53b 100644
--- a/drivers/raw/ntb/ntb.c
+++ b/drivers/raw/ntb/ntb.c
@@ -1398,6 +1398,10 @@ ntb_init_hw(struct rte_rawdev *dev, struct rte_pci_device *pci_dev)
 
 	/* Init doorbell. */
 	hw->db_valid_mask = RTE_LEN2MASK(hw->db_cnt, uint64_t);
+	/* Clear all valid doorbell bits before registering intr handler */
+	if (hw->ntb_ops->db_clear == NULL)
+		return -ENOTSUP;
+	(*hw->ntb_ops->db_clear)(dev, hw->db_valid_mask);
 
 	intr_handle = pci_dev->intr_handle;
 	/* Register callback func to eal lib */
-- 
2.25.1