[PATCH] net: stmmac: Read user ID muliple times if needed.

[Hans Andersson]

From: Hans Andersson <hans.andersson@xxxxxxxxxxxxxx>

When we read user ID / Synopsys ID we might still be in reset,
so read muliple times if needed.

Signed-off-by: Hans Andersson <hans.andersson@xxxxxxxxxxxxxx>
---
 drivers/net/ethernet/stmicro/stmmac/hwif.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/hwif.c b/drivers/net/ethernet/stmicro/stmmac/hwif.c
index 6c61b75..3347164 100644
--- a/drivers/net/ethernet/stmicro/stmmac/hwif.c
+++ b/drivers/net/ethernet/stmicro/stmmac/hwif.c
@@ -10,7 +10,16 @@
 
 static u32 stmmac_get_id(struct stmmac_priv *priv, u32 id_reg)
 {
-	u32 reg = readl(priv->ioaddr + id_reg);
+	u32 reg;
+	int i;
+
+	/* We might still be in reset when we read, */
+	/* so read multiple times if needed. */
+	for (i = 0; i < 10; i++) {
+		reg = readl(priv->ioaddr + id_reg);
+		if (reg)
+			break;
+	}
 
 	if (!reg) {
 		dev_info(priv->device, "Version ID not available\n");
-- 
2.17.1