net: stmmac: Collect DMA missing frames stats non-mutually

Every DW MAC IP-core has a register called like "Missed Frame and Buffer
Overflow Counter". It exposes two counters being incremented on each frame
dropped due to FIFO overflow or DMA Rx-descriptor unavailable (Rx MTL FIFO
flushing). They exist irrespective from the MMC module availability.
Moreover expose the statistics unavailable in the MAC Management Counters.

So let's convert the code collecting MAC Management/Debug and DMA-missing
frames statistics to being linear and not mutually exclusive.

Also note currently the DMA missing frames stats is collected for the old
DW MAC IP-core. This change is also a preparation before adding the
counters support for the rest of the DW controllers.

Fixes: 1c901a46d576 ("stmmac: add MMC support exported via ethtool (v3)")
Signed-off-by: Serge Semin <fancer.lancer@gmail.com>

1 files changed, 21 insertions, 22 deletions

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c
index 9881b8df1e64..b3ad74fe8f69 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c
@@ -537,10 +537,11 @@ static void stmmac_get_ethtool_stats(struct net_device *dev,
 	u32 rx_queues_count = priv->plat->rx_queues_to_use;
 	u32 tx_queues_count = priv->plat->tx_queues_to_use;
 	u64 napi_poll = 0, normal_irq_n = 0;
-	int i, j = 0, pos, ret;
 	unsigned long count;
 	unsigned int start;
+	int i, j = 0, pos;
 
+	/* Update the statistics by reading from the HW counters */
 	if (priv->dma_cap.asp) {
 		for (i = 0; i < STMMAC_SAFETY_FEAT_SIZE; i++) {
 			if (!stmmac_safety_feat_dump(priv, &priv->sstats, i,
@@ -549,32 +550,30 @@ static void stmmac_get_ethtool_stats(struct net_device *dev,
 		}
 	}
 
-	/* Update the DMA HW counters for dwmac10/100 */
-	ret = stmmac_dma_diagnostic_fr(priv, &priv->xstats, priv->ioaddr);
-	if (ret) {
-		/* If supported, for new GMAC chips expose the MMC counters */
-		if (priv->dma_cap.rmon) {
-			stmmac_mmc_read(priv, priv->mmcaddr, &priv->mmc);
+	if (priv->dma_cap.rmon) {
+		stmmac_mmc_read(priv, priv->mmcaddr, &priv->mmc);
 
-			for (i = 0; i < STMMAC_MMC_STATS_LEN; i++) {
-				char *p;
-				p = (char *)priv + stmmac_mmc[i].stat_offset;
+		for (i = 0; i < STMMAC_MMC_STATS_LEN; i++) {
+			char *p;
+			p = (char *)priv + stmmac_mmc[i].stat_offset;
 
-				data[j++] = (stmmac_mmc[i].sizeof_stat ==
-					     sizeof(u64)) ? (*(u64 *)p) :
-					     (*(u32 *)p);
-			}
-		}
-		if (priv->dma_cap.eee) {
-			int val = phylink_get_eee_err(priv->phylink);
-			if (val)
-				priv->xstats.phy_eee_wakeup_error_n = val;
+			data[j++] = (stmmac_mmc[i].sizeof_stat == sizeof(u64)) ?
+				    (*(u64 *)p) : (*(u32 *)p);
 		}
+	}
 
-		stmmac_mac_debug(priv, priv->ioaddr,
-				(void *)&priv->xstats,
-				rx_queues_count, tx_queues_count);
+	if (priv->dma_cap.eee) {
+		int val = phylink_get_eee_err(priv->phylink);
+		if (val)
+			priv->xstats.phy_eee_wakeup_error_n = val;
 	}
+
+	stmmac_mac_debug(priv, priv->ioaddr,
+			(void *)&priv->xstats,
+			rx_queues_count, tx_queues_count);
+
+	stmmac_dma_diagnostic_fr(priv, &priv->xstats, priv->ioaddr);
+
 	for (i = 0; i < STMMAC_STATS_LEN; i++) {
 		char *p = (char *)priv + stmmac_gstrings_stats[i].stat_offset;
 		data[j++] = (stmmac_gstrings_stats[i].sizeof_stat ==