From: Biju Das <biju.das.jz@...>

commit 0b81d67311676c9119ed3b027d1518e974dbca8e upstream.

The register for retrieving TX counters is present only on R-Car Gen3
and RZ/G2L; it is not present on R-Car Gen2.

Add the tx_counters hw feature bit to struct ravb_hw_info, to enable this
feature specifically for R-Car Gen3 now and later extend it to RZ/G2L.

Signed-off-by: Biju Das <biju.das.jz@...>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@...>
Reviewed-by: Andrew Lunn <andrew@...>
Signed-off-by: David S. Miller <davem@...>
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@...>
---
drivers/net/ethernet/renesas/ravb.h | 1 +
drivers/net/ethernet/renesas/ravb_main.c | 4 +++-
2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/renesas/ravb.h b/drivers/net/ethernet/renesas/ravb.h
index 9aee46e23105..3d87fb40b5c8 100644
--- a/drivers/net/ethernet/renesas/ravb.h
+++ b/drivers/net/ethernet/renesas/ravb.h
@@ -1001,6 +1001,7 @@ struct ravb_hw_info {

/* hardware features */
unsigned internal_delay:1; /* AVB-DMAC has internal delays */
+ unsigned tx_counters:1; /* E-MAC has TX counters */
};

struct ravb_private {
diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
index 838badff3c19..b16c179ba44c 100644
--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c
@@ -1630,13 +1630,14 @@ static u16 ravb_select_queue(struct net_device *ndev, struct sk_buff *skb,
static struct net_device_stats *ravb_get_stats(struct net_device *ndev)
{
struct ravb_private *priv = netdev_priv(ndev);
+ const struct ravb_hw_info *info = priv->info;
struct net_device_stats *nstats, *stats0, *stats1;

nstats = &ndev->stats;
stats0 = &priv->stats[RAVB_BE];
stats1 = &priv->stats[RAVB_NC];

- if (priv->chip_id == RCAR_GEN3) {
+ if (info->tx_counters) {
nstats->tx_dropped += ravb_read(ndev, TROCR);
ravb_write(ndev, 0, TROCR); /* (write clear) */
}
@@ -1935,6 +1936,7 @@ static const struct ravb_hw_info ravb_gen3_hw_info = {
.stats_len = ARRAY_SIZE(ravb_gstrings_stats),
.max_rx_len = RX_BUF_SZ + RAVB_ALIGN - 1,
.internal_delay = 1,
+ .tx_counters = 1,
};

static const struct ravb_hw_info ravb_gen2_hw_info = {
--
2.17.1