netdev - [PATCH] net: fec: Refactor MAC reset to function

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Message-ID: <20250121103857.12007-3-csokas.bence@prolan.hu>
Date: Tue, 21 Jan 2025 11:38:58 +0100
From: Csókás, Bence <csokas.bence@...lan.hu>
To: Jakub Kicinski <kuba@...nel.org>, Laurent Badel <laurentbadel@...on.com>,
	<imx@...ts.linux.dev>, <netdev@...r.kernel.org>,
	<linux-kernel@...r.kernel.org>
CC: Csókás, Bence <csokas.bence@...lan.hu>, Wei Fang
	<wei.fang@....com>, Shenwei Wang <shenwei.wang@....com>, Clark Wang
	<xiaoning.wang@....com>, Andrew Lunn <andrew+netdev@...n.ch>, "David S.
 Miller" <davem@...emloft.net>, Eric Dumazet <edumazet@...gle.com>, "Paolo
 Abeni" <pabeni@...hat.com>
Subject: [PATCH] net: fec: Refactor MAC reset to function

The core is reset both in `fec_restart()`
(called on link-up) and `fec_stop()`
(going to sleep, driver remove etc.).
These two functions had their separate
implementations, which was at first only
a register write and a `udelay()` (and
the accompanying block comment).
However, since then we got soft-reset
(MAC disable) and Wake-on-LAN support,
which meant that these implementations
diverged, often causing bugs. For instance,
as of now, `fec_stop()` does not check for
`FEC_QUIRK_NO_HARD_RESET`. To eliminate
this bug-source, refactor implementation
to a common function.

Fixes: c730ab423bfa ("net: fec: Fix temporary RMII clock reset on link up")
Signed-off-by: Csókás, Bence <csokas.bence@...lan.hu>
---

Notes:
    Recommended options for this patch:
    `--color-moved --color-moved-ws=allow-indentation-change`

 drivers/net/ethernet/freescale/fec_main.c | 50 +++++++++++------------
 1 file changed, 23 insertions(+), 27 deletions(-)

diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index 68725506a095..850ef3de74ec 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -1064,6 +1064,27 @@ static void fec_enet_enable_ring(struct net_device *ndev)
 	}
 }
 
+/* Whack a reset.  We should wait for this.
+ * For i.MX6SX SOC, enet use AXI bus, we use disable MAC
+ * instead of reset MAC itself.
+ */
+static void fec_ctrl_reset(struct fec_enet_private *fep, bool wol)
+{
+	if (!wol || !(fep->wol_flag & FEC_WOL_FLAG_SLEEP_ON)) {
+		if (fep->quirks & FEC_QUIRK_HAS_MULTI_QUEUES ||
+		    ((fep->quirks & FEC_QUIRK_NO_HARD_RESET) && fep->link)) {
+			writel(0, fep->hwp + FEC_ECNTRL);
+		} else {
+			writel(FEC_ECR_RESET, fep->hwp + FEC_ECNTRL);
+			udelay(10);
+		}
+	} else {
+		val = readl(fep->hwp + FEC_ECNTRL);
+		val |= (FEC_ECR_MAGICEN | FEC_ECR_SLEEP);
+		writel(val, fep->hwp + FEC_ECNTRL);
+	}
+}
+
 /*
  * This function is called to start or restart the FEC during a link
  * change, transmit timeout, or to reconfigure the FEC.  The network
@@ -1080,17 +1101,7 @@ fec_restart(struct net_device *ndev)
 	if (fep->bufdesc_ex)
 		fec_ptp_save_state(fep);
 
-	/* Whack a reset.  We should wait for this.
-	 * For i.MX6SX SOC, enet use AXI bus, we use disable MAC
-	 * instead of reset MAC itself.
-	 */
-	if (fep->quirks & FEC_QUIRK_HAS_MULTI_QUEUES ||
-	    ((fep->quirks & FEC_QUIRK_NO_HARD_RESET) && fep->link)) {
-		writel(0, fep->hwp + FEC_ECNTRL);
-	} else {
-		writel(1, fep->hwp + FEC_ECNTRL);
-		udelay(10);
-	}
+	fec_ctrl_reset(fep, false);
 
 	/*
 	 * enet-mac reset will reset mac address registers too,
@@ -1344,22 +1355,7 @@ fec_stop(struct net_device *ndev)
 	if (fep->bufdesc_ex)
 		fec_ptp_save_state(fep);
 
-	/* Whack a reset.  We should wait for this.
-	 * For i.MX6SX SOC, enet use AXI bus, we use disable MAC
-	 * instead of reset MAC itself.
-	 */
-	if (!(fep->wol_flag & FEC_WOL_FLAG_SLEEP_ON)) {
-		if (fep->quirks & FEC_QUIRK_HAS_MULTI_QUEUES) {
-			writel(0, fep->hwp + FEC_ECNTRL);
-		} else {
-			writel(FEC_ECR_RESET, fep->hwp + FEC_ECNTRL);
-			udelay(10);
-		}
-	} else {
-		val = readl(fep->hwp + FEC_ECNTRL);
-		val |= (FEC_ECR_MAGICEN | FEC_ECR_SLEEP);
-		writel(val, fep->hwp + FEC_ECNTRL);
-	}
+	fec_ctrl_reset(fep, true);
 	writel(fep->phy_speed, fep->hwp + FEC_MII_SPEED);
 	writel(FEC_DEFAULT_IMASK, fep->hwp + FEC_IMASK);
 
-- 
2.48.1