From eb38401c779d350e9e31396471ea072fa29aec9b Mon Sep 17 00:00:00 2001
From: Jose Abreu <Jose.Abreu@synopsys.com>
Date: Fri, 18 May 2018 16:54:38 +0100
Subject: [PATCH] net: stmmac: Populate missing callbacks in HWIF
 initialization

Some HW specific setups, like sun8i, do not populate all the necessary
callbacks, which is what HWIF helpers were expecting.

Fix this by always trying to get the generic helpers and populate them
if they were not previously populated by HW specific setup.

Signed-off-by: Jose Abreu <joabreu@synopsys.com>
Fixes: 5f0456b43140 ("net: stmmac: Implement logic to automatically
select HW Interface")
Reported-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Tested-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Cc: Corentin Labbe <clabbe.montjoie@gmail.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Joao Pinto <jpinto@synopsys.com>
Cc: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Cc: Alexandre Torgue <alexandre.torgue@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 drivers/net/ethernet/stmicro/stmmac/hwif.c | 38 +++++++++++++---------
 1 file changed, 22 insertions(+), 16 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/hwif.c b/drivers/net/ethernet/stmicro/stmmac/hwif.c
index 23a12649e247..14770fc8865e 100644
--- a/drivers/net/ethernet/stmicro/stmmac/hwif.c
+++ b/drivers/net/ethernet/stmicro/stmmac/hwif.c
@@ -189,13 +189,16 @@ int stmmac_hwif_init(struct stmmac_priv *priv)
 	bool needs_gmac = priv->plat->has_gmac;
 	const struct stmmac_hwif_entry *entry;
 	struct mac_device_info *mac;
+	bool needs_setup = true;
 	int i, ret;
 	u32 id;
 
 	if (needs_gmac) {
 		id = stmmac_get_id(priv, GMAC_VERSION);
-	} else {
+	} else if (needs_gmac4) {
 		id = stmmac_get_id(priv, GMAC4_VERSION);
+	} else {
+		id = 0;
 	}
 
 	/* Save ID for later use */
@@ -209,13 +212,12 @@ int stmmac_hwif_init(struct stmmac_priv *priv)
 
 	/* Check for HW specific setup first */
 	if (priv->plat->setup) {
-		priv->hw = priv->plat->setup(priv);
-		if (!priv->hw)
-			return -ENOMEM;
-		return 0;
+		mac = priv->plat->setup(priv);
+		needs_setup = false;
+	} else {
+		mac = devm_kzalloc(priv->device, sizeof(*mac), GFP_KERNEL);
 	}
 
-	mac = devm_kzalloc(priv->device, sizeof(*mac), GFP_KERNEL);
 	if (!mac)
 		return -ENOMEM;
 
@@ -227,24 +229,28 @@ int stmmac_hwif_init(struct stmmac_priv *priv)
 			continue;
 		if (needs_gmac4 ^ entry->gmac4)
 			continue;
-		if (id < entry->min_id)
+		/* Use synopsys_id var because some setups can override this */
+		if (priv->synopsys_id < entry->min_id)
 			continue;
 
-		mac->desc = entry->desc;
-		mac->dma = entry->dma;
-		mac->mac = entry->mac;
-		mac->ptp = entry->hwtimestamp;
-		mac->mode = entry->mode;
-		mac->tc = entry->tc;
+		/* Only use generic HW helpers if needed */
+		mac->desc = mac->desc ? : entry->desc;
+		mac->dma = mac->dma ? : entry->dma;
+		mac->mac = mac->mac ? : entry->mac;
+		mac->ptp = mac->ptp ? : entry->hwtimestamp;
+		mac->mode = mac->mode ? : entry->mode;
+		mac->tc = mac->tc ? : entry->tc;
 
 		priv->hw = mac;
 		priv->ptpaddr = priv->ioaddr + entry->regs.ptp_off;
 		priv->mmcaddr = priv->ioaddr + entry->regs.mmc_off;
 
 		/* Entry found */
-		ret = entry->setup(priv);
-		if (ret)
-			return ret;
+		if (needs_setup) {
+			ret = entry->setup(priv);
+			if (ret)
+				return ret;
+		}
 
 		/* Run quirks, if needed */
 		if (entry->quirks) {