openwrt/target/linux/generic/backport-6.6/790-21-v6.9-net-dsa-mt7530-do-not-use-SW_PHY_RST-to-reset-MT7531.patch

From 80f4f866d7dad41b12cf37476c38766a89b8b5c4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ar=C4=B1n=C3=A7=20=C3=9CNAL?= <arinc.unal@arinc9.com>
Date: Fri, 1 Mar 2024 12:42:59 +0200
Subject: [PATCH 21/30] net: dsa: mt7530: do not use SW_PHY_RST to reset MT7531
 switch
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According to the document MT7531 Reference Manual for Development Board
v1.0, the SW_PHY_RST bit on the SYS_CTRL register doesn't exist for
MT7531. This is likely why forcing link down on all ports is necessary for
MT7531.

Therefore, do not set SW_PHY_RST on mt7531_setup().

Signed-off-by: Arınç ÜNAL <arinc.unal@arinc9.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
---
 drivers/net/dsa/mt7530.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

--- a/drivers/net/dsa/mt7530.c
+++ b/drivers/net/dsa/mt7530.c
@@ -2657,14 +2657,12 @@ mt7531_setup(struct dsa_switch *ds)
 	val = mt7530_read(priv, MT7531_TOP_SIG_SR);
 	priv->p5_sgmii = !!(val & PAD_DUAL_SGMII_EN);
 
-	/* all MACs must be forced link-down before sw reset */
+	/* Force link down on all ports before internal reset */
 	for (i = 0; i < MT7530_NUM_PORTS; i++)
 		mt7530_write(priv, MT7530_PMCR_P(i), MT7531_FORCE_LNK);
 
 	/* Reset the switch through internal reset */
-	mt7530_write(priv, MT7530_SYS_CTRL,
-		     SYS_CTRL_PHY_RST | SYS_CTRL_SW_RST |
-		     SYS_CTRL_REG_RST);
+	mt7530_write(priv, MT7530_SYS_CTRL, SYS_CTRL_SW_RST | SYS_CTRL_REG_RST);
 
 	if (!priv->p5_sgmii) {
 		mt7531_pll_setup(priv);