releases/5.10.20/net-axienet-handle-deferred-probe-on-clock-properly.patch

From 2ffe7b230b60257a1e29ac1b76226edd121c1cb9 Mon Sep 17 00:00:00 2001
From: Sasha Levin <sashal@kernel.org>
Date: Fri, 12 Feb 2021 18:17:48 -0600
Subject: net: axienet: Handle deferred probe on clock properly

From: Robert Hancock <robert.hancock@calian.com>

[ Upstream commit 57baf8cc70ea4cf5503c9d42f31f6a86d7f5ff1a ]

This driver is set up to use a clock mapping in the device tree if it is
present, but still work without one for backward compatibility. However,
if getting the clock returns -EPROBE_DEFER, then we need to abort and
return that error from our driver initialization so that the probe can
be retried later after the clock is set up.

Move clock initialization to earlier in the process so we do not waste as
much effort if the clock is not yet available. Switch to use
devm_clk_get_optional and abort initialization on any error reported.
Also enable the clock regardless of whether the controller is using an MDIO
bus, as the clock is required in any case.

Fixes: 09a0354cadec267be7f ("net: axienet: Use clock framework to get device clock rate")
Signed-off-by: Robert Hancock <robert.hancock@calian.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 .../net/ethernet/xilinx/xilinx_axienet_main.c | 26 +++++++++----------
 1 file changed, 12 insertions(+), 14 deletions(-)

diff --git a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c
index 9aafd3ecdaa4d..eea0bb7c23ede 100644
--- a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c
+++ b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c
@@ -1805,6 +1805,18 @@ static int axienet_probe(struct platform_device *pdev)
 	lp->options = XAE_OPTION_DEFAULTS;
 	lp->rx_bd_num = RX_BD_NUM_DEFAULT;
 	lp->tx_bd_num = TX_BD_NUM_DEFAULT;
+
+	lp->clk = devm_clk_get_optional(&pdev->dev, NULL);
+	if (IS_ERR(lp->clk)) {
+		ret = PTR_ERR(lp->clk);
+		goto free_netdev;
+	}
+	ret = clk_prepare_enable(lp->clk);
+	if (ret) {
+		dev_err(&pdev->dev, "Unable to enable clock: %d\n", ret);
+		goto free_netdev;
+	}
+
 	/* Map device registers */
 	ethres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	lp->regs = devm_ioremap_resource(&pdev->dev, ethres);
@@ -1980,20 +1992,6 @@ static int axienet_probe(struct platform_device *pdev)
 
 	lp->phy_node = of_parse_phandle(pdev->dev.of_node, "phy-handle", 0);
 	if (lp->phy_node) {
-		lp->clk = devm_clk_get(&pdev->dev, NULL);
-		if (IS_ERR(lp->clk)) {
-			dev_warn(&pdev->dev, "Failed to get clock: %ld\n",
-				 PTR_ERR(lp->clk));
-			lp->clk = NULL;
-		} else {
-			ret = clk_prepare_enable(lp->clk);
-			if (ret) {
-				dev_err(&pdev->dev, "Unable to enable clock: %d\n",
-					ret);
-				goto free_netdev;
-			}
-		}
-
 		ret = axienet_mdio_setup(lp);
 		if (ret)
 			dev_warn(&pdev->dev,
-- 
2.27.0