[net-next, PATCH 1/2] net: netsec: initialize tx ring on ndo_open

[Ilias Apalodimas]

Since we changed the Tx ring handling and now depend not bit31 to figure
out the owner of the descriptor, we should initialize this every time
the device goes down-up instead of doing it once on driver init. If the
value is not correctly initialized the device won't have any available
descriptors

Fixes: 35e07d23473972b8876f98bcfc631ebcf779e870 ("net: socionext: remove mmio 
reads on Tx")

Signed-off-by: Ilias Apalodimas <ilias.apalodi...@linaro.org>
---
 drivers/net/ethernet/socionext/netsec.c | 32 ++++++++++++++-----------
 1 file changed, 18 insertions(+), 14 deletions(-)

diff --git a/drivers/net/ethernet/socionext/netsec.c 
b/drivers/net/ethernet/socionext/netsec.c
index cba5881b2746..a10ef700f16d 100644
--- a/drivers/net/ethernet/socionext/netsec.c
+++ b/drivers/net/ethernet/socionext/netsec.c
@@ -1029,7 +1029,6 @@ static void netsec_free_dring(struct netsec_priv *priv, 
int id)
 static int netsec_alloc_dring(struct netsec_priv *priv, enum ring_id id)
 {
        struct netsec_desc_ring *dring = &priv->desc_ring[id];
-       int i;
 
        dring->vaddr = dma_alloc_coherent(priv->dev, DESC_SZ * DESC_NUM,
                                          &dring->desc_dma, GFP_KERNEL);
@@ -1040,19 +1039,6 @@ static int netsec_alloc_dring(struct netsec_priv *priv, 
enum ring_id id)
        if (!dring->desc)
                goto err;
 
-       if (id == NETSEC_RING_TX) {
-               for (i = 0; i < DESC_NUM; i++) {
-                       struct netsec_de *de;
-
-                       de = dring->vaddr + (DESC_SZ * i);
-                       /* de->attr is not going to be accessed by the NIC
-                        * until netsec_set_tx_de() is called.
-                        * No need for a dma_wmb() here
-                        */
-                       de->attr = 1U << NETSEC_TX_SHIFT_OWN_FIELD;
-               }
-       }
-
        return 0;
 err:
        netsec_free_dring(priv, id);
@@ -1060,6 +1046,23 @@ static int netsec_alloc_dring(struct netsec_priv *priv, 
enum ring_id id)
        return -ENOMEM;
 }
 
+static void netsec_setup_tx_dring(struct netsec_priv *priv)
+{
+       struct netsec_desc_ring *dring = &priv->desc_ring[NETSEC_RING_TX];
+       int i;
+
+       for (i = 0; i < DESC_NUM; i++) {
+               struct netsec_de *de;
+
+               de = dring->vaddr + (DESC_SZ * i);
+               /* de->attr is not going to be accessed by the NIC
+                * until netsec_set_tx_de() is called.
+                * No need for a dma_wmb() here
+                */
+               de->attr = 1U << NETSEC_TX_SHIFT_OWN_FIELD;
+       }
+}
+
 static int netsec_setup_rx_dring(struct netsec_priv *priv)
 {
        struct netsec_desc_ring *dring = &priv->desc_ring[NETSEC_RING_RX];
@@ -1361,6 +1364,7 @@ static int netsec_netdev_open(struct net_device *ndev)
 
        pm_runtime_get_sync(priv->dev);
 
+       netsec_setup_tx_dring(priv);
        ret = netsec_setup_rx_dring(priv);
        if (ret) {
                netif_err(priv, probe, priv->ndev,
-- 
2.20.1