[PATCH net-next] net: stmmac: Populate missing callbacks in HWIF initialization

[Jose Abreu <Jose.Abreu@synopsys.com>]

Some HW specific setusp, 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>
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>
---
Hi Corentin,

Please check if this patch makes sun8i work again.

Thanks and Best Regards,
Jose Miguel Abreu
---
 drivers/net/ethernet/stmicro/stmmac/hwif.c |   38 ++++++++++++++++-----------
 1 files changed, 22 insertions(+), 16 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/hwif.c b/drivers/net/ethernet/stmicro/stmmac/hwif.c
index 9acc8d2..bf87571 100644
--- a/drivers/net/ethernet/stmicro/stmmac/hwif.c
+++ b/drivers/net/ethernet/stmicro/stmmac/hwif.c
@@ -163,13 +163,16 @@ 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 */
@@ -177,13 +180,12 @@ 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;
 
@@ -195,22 +197,26 @@ 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;
 
 		/* 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) {
-- 
1.7.1