Ensure that received Subordinate Command-Response Queue
entries are properly read in order by the driver.

Signed-off-by: Thomas Falcon <tlfal...@linux.ibm.com>
---
 drivers/net/ethernet/ibm/ibmvnic.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/net/ethernet/ibm/ibmvnic.c 
b/drivers/net/ethernet/ibm/ibmvnic.c
index da15913879f8..5647f54bf387 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c
@@ -2391,6 +2391,8 @@ static int ibmvnic_poll(struct napi_struct *napi, int 
budget)
 
                if (!pending_scrq(adapter, adapter->rx_scrq[scrq_num]))
                        break;
+               /* ensure that we do not prematurely exit the polling loop */
+               dma_rmb();
                next = ibmvnic_next_scrq(adapter, adapter->rx_scrq[scrq_num]);
                rx_buff =
                    (struct ibmvnic_rx_buff *)be64_to_cpu(next->
@@ -3087,6 +3089,8 @@ static int ibmvnic_complete_tx(struct ibmvnic_adapter 
*adapter,
                int num_entries = 0;
 
                next = ibmvnic_next_scrq(adapter, scrq);
+               /* ensure that we are reading the correct queue entry */
+               dma_rmb();
                for (i = 0; i < next->tx_comp.num_comps; i++) {
                        if (next->tx_comp.rcs[i]) {
                                dev_err(dev, "tx error %x\n",
-- 
2.26.2

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