[PATCH v3 07/11] net/octeon_ep: flush pending DMA operations

[Sathesh Edara]

Flushes the pending DMA operations while reading
the packets by reading control and status register.

Signed-off-by: Sathesh Edara <sed...@marvell.com>
---
 drivers/net/octeon_ep/otx_ep_common.h | 8 ++++++++
 drivers/net/octeon_ep/otx_ep_rxtx.c   | 4 ++++
 2 files changed, 12 insertions(+)

diff --git a/drivers/net/octeon_ep/otx_ep_common.h 
b/drivers/net/octeon_ep/otx_ep_common.h
index 76528ed49d..444136923f 100644
--- a/drivers/net/octeon_ep/otx_ep_common.h
+++ b/drivers/net/octeon_ep/otx_ep_common.h
@@ -345,6 +345,14 @@ struct otx_ep_droq {
         */
        void *pkts_sent_reg;
 
+       /** Handle DMA incompletion during pkt reads.
+        * This variable is used to initiate a sent_reg_read
+        * that completes pending dma
+        * this variable is used as lvalue so compiler cannot optimize
+        * the reads.
+        */
+       uint32_t sent_reg_val;
+
        /* Statistics for this DROQ. */
        struct otx_ep_droq_stats stats;
 
diff --git a/drivers/net/octeon_ep/otx_ep_rxtx.c 
b/drivers/net/octeon_ep/otx_ep_rxtx.c
index c4153bd583..ca968f6fe7 100644
--- a/drivers/net/octeon_ep/otx_ep_rxtx.c
+++ b/drivers/net/octeon_ep/otx_ep_rxtx.c
@@ -917,6 +917,10 @@ otx_ep_droq_read_packet(struct otx_ep_device *otx_ep,
                struct rte_mbuf *first_buf = NULL;
                struct rte_mbuf *last_buf = NULL;
 
+               /* csr read helps to flush pending dma */
+               droq->sent_reg_val = rte_read32(droq->pkts_sent_reg);
+               rte_rmb();
+
                while (pkt_len < total_pkt_len) {
                        int cpy_len = 0;
 
-- 
2.31.1