Re: [PATCH net v3] net: dpaa: fix mode setting

Before converting to the phylink interface, the init function would have
set a non-reserved I/F mode in the maccfg2 register. After converting to
phylink, 0 is written as mode, which is a reserved value (although it's
the hardware default). Without a valid mode, a SGMII link is never
established between the MAC and the PHY and thus .link_up() is never
called which could set the correct mode according to the actual speed.

Fix it by setting the maximum speed of the phy_interface_t in use in
.mac_config() - just like the driver did before the phylink conversion.

Fixes: 5d93cfcf7360 ("net: dpaa: Convert to phylink")
Suggested-by: Sean Anderson <sean.anderson@linux.dev>
Signed-off-by: Michael Walle <mwalle@kernel.org>
---
I didn't grab Sean's Rb tag as this is somewhat different.

Changes in v3:
  - keep the mode setting also in .adjust_link().
  - reword the commit message, to be (hopefully) more precise
  - Link to v2: https://lore.kernel.org/r/20260710143430.2276141-1-mwalle@kernel.org/ (local)

Changes in v2:
  - the setting is/was based on the maximum speed, not the current
    speed. thus, move the setting into mac_config().
  - Link to v1: https://lore.kernel.org/r/20260706121011.1948906-1-mwalle@kernel.org/ (local)

  .../net/ethernet/freescale/fman/fman_dtsec.c    | 17 ++++++++++++-----
  1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/freescale/fman/fman_dtsec.c b/drivers/net/ethernet/freescale/fman/fman_dtsec.c
index fe35703c509e..b8d70c0ecb6c 100644
--- a/drivers/net/ethernet/freescale/fman/fman_dtsec.c
+++ b/drivers/net/ethernet/freescale/fman/fman_dtsec.c

@@ -900,22 +900,28 @@ static void dtsec_mac_config(struct phylink_config *config, unsigned int mode,
  {
  	struct mac_device *mac_dev = fman_config_to_mac(config);
  	struct dtsec_regs __iomem *regs = mac_dev->fman_mac->regs;
-	u32 tmp;
+	u32 ecntrl, maccfg2;
+
+	maccfg2 = ioread32be(&regs->maccfg2);
+	maccfg2 &= ~(MACCFG2_NIBBLE_MODE | MACCFG2_BYTE_MODE);
  
  	switch (state->interface) {
  	case PHY_INTERFACE_MODE_RMII:
-		tmp = DTSEC_ECNTRL_RMM;
+		ecntrl = DTSEC_ECNTRL_RMM;
+		maccfg2 |= MACCFG2_NIBBLE_MODE;
  		break;
  	case PHY_INTERFACE_MODE_RGMII:
  	case PHY_INTERFACE_MODE_RGMII_ID:
  	case PHY_INTERFACE_MODE_RGMII_RXID:
  	case PHY_INTERFACE_MODE_RGMII_TXID:
-		tmp = DTSEC_ECNTRL_GMIIM | DTSEC_ECNTRL_RPM;
+		ecntrl = DTSEC_ECNTRL_GMIIM | DTSEC_ECNTRL_RPM;
+		maccfg2 |= MACCFG2_BYTE_MODE;
  		break;
  	case PHY_INTERFACE_MODE_SGMII:
  	case PHY_INTERFACE_MODE_1000BASEX:
  	case PHY_INTERFACE_MODE_2500BASEX:
-		tmp = DTSEC_ECNTRL_TBIM | DTSEC_ECNTRL_SGMIIM;
+		ecntrl = DTSEC_ECNTRL_TBIM | DTSEC_ECNTRL_SGMIIM;
+		maccfg2 |= MACCFG2_BYTE_MODE;
  		break;
  	default:
  		dev_warn(mac_dev->dev, "cannot configure dTSEC for %s\n",

@@ -923,7 +929,8 @@ static void dtsec_mac_config(struct phylink_config *config, unsigned int mode,
  		return;
  	}
  
-	iowrite32be(tmp, &regs->ecntrl);
+	iowrite32be(ecntrl, &regs->ecntrl);
+	iowrite32be(maccfg2, &regs->maccfg2);
  }
  
  static void dtsec_link_up(struct phylink_config *config, struct phy_device *phy,