[PATCH v1 10/26] net: dsa: microchip: ksz8: refactor ksz8_fdb_dump()

[Oleksij Rempel]

After fixing different bugs we can refactor this function:
- be paranoid - read only max possibly amount of entries supported by
  the HW.
- pass error values returned by regmap

Signed-off-by: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
---
 drivers/net/dsa/microchip/ksz8795.c     | 41 ++++++++++++++-----------
 drivers/net/dsa/microchip/ksz8795_reg.h |  1 +
 2 files changed, 24 insertions(+), 18 deletions(-)

diff --git a/drivers/net/dsa/microchip/ksz8795.c b/drivers/net/dsa/microchip/ksz8795.c
index 736cf4e54333..308b46bb2ce5 100644
--- a/drivers/net/dsa/microchip/ksz8795.c
+++ b/drivers/net/dsa/microchip/ksz8795.c
@@ -949,26 +949,31 @@ void ksz8_flush_dyn_mac_table(struct ksz_device *dev, int port)
 int ksz8_fdb_dump(struct ksz_device *dev, int port,
 		  dsa_fdb_dump_cb_t *cb, void *data)
 {
-	int ret = 0;
-	u16 i = 0;
-	u16 entries = 0;
-	u8 src_port;
-	u8 mac[ETH_ALEN];
+	u16 i, entries = 0;
+	int ret;
 
-	do {
-		ret = ksz8_r_dyn_mac_table(dev, i, mac, &src_port,
-					   &entries);
-		if (!ret && port == src_port) {
-			ret = cb(mac, 0, false, data);
-			if (ret)
-				break;
-		}
-		i++;
-	} while (i < entries);
-	if (i >= entries)
-		ret = 0;
+	for (i = 0; i < KSZ8_DYN_MAC_ENTRIES; i++) {
+		u8 mac[ETH_ALEN];
+		u8 src_port;
 
-	return ret;
+		ret = ksz8_r_dyn_mac_table(dev, i, mac, &src_port, &entries);
+		if (ret == -ENXIO)
+			return 0;
+		if (ret)
+			return ret;
+
+		if (i >= entries)
+			return 0;
+
+		if (port != src_port)
+			continue;
+
+		ret = cb(mac, 0, false, data);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
 }
 
 int ksz8_mdb_add(struct ksz_device *dev, int port,
diff --git a/drivers/net/dsa/microchip/ksz8795_reg.h b/drivers/net/dsa/microchip/ksz8795_reg.h
index 7a57c6088f80..0bdceb534192 100644
--- a/drivers/net/dsa/microchip/ksz8795_reg.h
+++ b/drivers/net/dsa/microchip/ksz8795_reg.h
@@ -811,5 +811,6 @@
 #define TAIL_TAG_LOOKUP			BIT(7)
 
 #define FID_ENTRIES			128
+#define KSZ8_DYN_MAC_ENTRIES		1024
 
 #endif
-- 
2.30.2