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From:   Claudiu <claudiu.beznea@tuxon.dev>
To:     s.shtylyov@omp.ru, davem@davemloft.net, edumazet@google.com,
        kuba@kernel.org, pabeni@redhat.com,
        claudiu.beznea.uj@bp.renesas.com, yoshihiro.shimoda.uh@renesas.com,
        wsa+renesas@sang-engineering.com,
        niklas.soderlund+renesas@ragnatech.se, biju.das.jz@bp.renesas.com,
        prabhakar.mahadev-lad.rj@bp.renesas.com,
        mitsuhiro.kimura.kc@renesas.com, geert+renesas@glider.be
Cc:     netdev@vger.kernel.org, linux-renesas-soc@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH net 1/2] net: ravb: Wait for operation mode to be applied
Date:   Thu, 14 Dec 2023 13:31:36 +0200
Message-Id: <20231214113137.2450292-2-claudiu.beznea.uj@bp.renesas.com>
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From: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>

CSR.OPS bits specify the current operating mode and (according to
documentation) they are updated when the operating mode change request
is processed. Thus, check CSR.OPS before proceeding.

Fixes: 568b3ce7a8ef ("ravb: factor out register bit twiddling code")
Fixes: 0184165b2f42 ("ravb: add sleep PM suspend/resume support")
Fixes: 7e09a052dc4e ("ravb: Exclude gPTP feature support for RZ/G2L")
Fixes: 3e3d647715d4 ("ravb: add wake-on-lan support via magic packet")
Fixes: c156633f1353 ("Renesas Ethernet AVB driver proper")
Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
---
 drivers/net/ethernet/renesas/ravb_main.c | 47 ++++++++++++++++++++----
 1 file changed, 39 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
index 9178f6d60e74..ce95eb5af354 100644
--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c
@@ -683,8 +683,11 @@ static int ravb_dmac_init(struct net_device *ndev)
 
 	/* Setting the control will start the AVB-DMAC process. */
 	ravb_modify(ndev, CCC, CCC_OPC, CCC_OPC_OPERATION);
+	error = ravb_wait(ndev, CSR, CSR_OPS, CSR_OPS_OPERATION);
+	if (error)
+		netdev_err(ndev, "failed to switch device to operation mode\n");
 
-	return 0;
+	return error;
 }
 
 static void ravb_get_tx_tstamp(struct net_device *ndev)
@@ -1744,6 +1747,18 @@ static inline int ravb_hook_irq(unsigned int irq, irq_handler_t handler,
 	return error;
 }
 
+static int ravb_set_reset_mode(struct net_device *ndev)
+{
+	int error;
+
+	ravb_write(ndev, CCC_OPC_RESET, CCC);
+	error = ravb_wait(ndev, CSR, CSR_OPS, CSR_OPS_RESET);
+	if (error)
+		netdev_err(ndev, "failed to switch device to reset mode\n");
+
+	return error;
+}
+
 /* Network device open function for Ethernet AVB */
 static int ravb_open(struct net_device *ndev)
 {
@@ -2551,10 +2566,11 @@ static int ravb_set_gti(struct net_device *ndev)
 	return 0;
 }
 
-static void ravb_set_config_mode(struct net_device *ndev)
+static int ravb_set_config_mode(struct net_device *ndev)
 {
 	struct ravb_private *priv = netdev_priv(ndev);
 	const struct ravb_hw_info *info = priv->info;
+	int error;
 
 	if (info->gptp) {
 		ravb_modify(ndev, CCC, CCC_OPC, CCC_OPC_CONFIG);
@@ -2566,6 +2582,12 @@ static void ravb_set_config_mode(struct net_device *ndev)
 	} else {
 		ravb_modify(ndev, CCC, CCC_OPC, CCC_OPC_CONFIG);
 	}
+
+	error = ravb_wait(ndev, CSR, CSR_OPS, CSR_OPS_CONFIG);
+	if (error)
+		netdev_err(ndev, "failed to switch device to config mode\n");
+
+	return error;
 }
 
 /* Set tx and rx clock internal delay modes */
@@ -2785,7 +2807,9 @@ static int ravb_probe(struct platform_device *pdev)
 	ndev->ethtool_ops = &ravb_ethtool_ops;
 
 	/* Set AVB config mode */
-	ravb_set_config_mode(ndev);
+	error = ravb_set_config_mode(ndev);
+	if (error)
+		goto out_disable_refclk;
 
 	if (info->gptp || info->ccc_gac) {
 		/* Set GTI value */
@@ -2893,6 +2917,7 @@ static void ravb_remove(struct platform_device *pdev)
 	struct net_device *ndev = platform_get_drvdata(pdev);
 	struct ravb_private *priv = netdev_priv(ndev);
 	const struct ravb_hw_info *info = priv->info;
+	int error;
 
 	unregister_netdev(ndev);
 	if (info->nc_queues)
@@ -2908,8 +2933,9 @@ static void ravb_remove(struct platform_device *pdev)
 	dma_free_coherent(ndev->dev.parent, priv->desc_bat_size, priv->desc_bat,
 			  priv->desc_bat_dma);
 
-	/* Set reset mode */
-	ravb_write(ndev, CCC_OPC_RESET, CCC);
+	error = ravb_set_reset_mode(ndev);
+	if (error)
+		netdev_err(ndev, "Failed to reset ndev\n");
 
 	clk_disable_unprepare(priv->gptp_clk);
 	clk_disable_unprepare(priv->refclk);
@@ -2991,8 +3017,11 @@ static int __maybe_unused ravb_resume(struct device *dev)
 	int ret = 0;
 
 	/* If WoL is enabled set reset mode to rearm the WoL logic */
-	if (priv->wol_enabled)
-		ravb_write(ndev, CCC_OPC_RESET, CCC);
+	if (priv->wol_enabled) {
+		ret = ravb_set_reset_mode(ndev);
+		if (ret)
+			return ret;
+	}
 
 	/* All register have been reset to default values.
 	 * Restore all registers which where setup at probe time and
@@ -3000,7 +3029,9 @@ static int __maybe_unused ravb_resume(struct device *dev)
 	 */
 
 	/* Set AVB config mode */
-	ravb_set_config_mode(ndev);
+	ret = ravb_set_config_mode(ndev);
+	if (ret)
+		return ret;
 
 	if (info->gptp || info->ccc_gac) {
 		/* Set GTI value */
-- 
2.39.2