6.8-stable review patch. If anyone has any objections, please let me know. ------------------ From: Arınç ÜNAL <arinc.unal@xxxxxxxxxx> commit 5f563c31ff0c40ce395d0bae7daa94c7950dac97 upstream. The MT7530 switch after reset initialises with a core clock frequency that works with a 25MHz XTAL connected to it. For 40MHz XTAL, the core clock frequency must be set to 500MHz. The mt7530_pll_setup() function is responsible of setting the core clock frequency. Currently, it runs on MT7530 with 25MHz and 40MHz XTAL. This causes MT7530 switch with 25MHz XTAL to egress and ingress frames improperly. Introduce a check to run it only on MT7530 with 40MHz XTAL. The core clock frequency is set by writing to a switch PHY's register. Access to the PHY's register is done via the MDIO bus the switch is also on. Therefore, it works only when the switch makes switch PHYs listen on the MDIO bus the switch is on. This is controlled either by the state of the ESW_P1_LED_1 pin after reset deassertion or modifying bit 5 of the modifiable trap register. When ESW_P1_LED_1 is pulled high, PHY indirect access is used. That means accessing PHY registers via the PHY indirect access control register of the switch. When ESW_P1_LED_1 is pulled low, PHY direct access is used. That means accessing PHY registers via the MDIO bus the switch is on. For MT7530 switch with 40MHz XTAL on a board with ESW_P1_LED_1 pulled high, the core clock frequency won't be set to 500MHz, causing the switch to egress and ingress frames improperly. Run mt7530_pll_setup() after PHY direct access is set on the modifiable trap register. With these two changes, all MT7530 switches with 25MHz and 40MHz, and P1_LED_1 pulled high or low, will egress and ingress frames properly. Link: https://github.com/BPI-SINOVOIP/BPI-R2-bsp/blob/4a5dd143f2172ec97a2872fa29c7c4cd520f45b5/linux-mt/drivers/net/ethernet/mediatek/gsw_mt7623.c#L1039 Fixes: b8f126a8d543 ("net-next: dsa: add dsa support for Mediatek MT7530 switch") Signed-off-by: Arınç ÜNAL <arinc.unal@xxxxxxxxxx> Link: https://lore.kernel.org/r/20240320-for-net-mt7530-fix-25mhz-xtal-with-direct-phy-access-v1-1-d92f605f1160@xxxxxxxxxx Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx> Signed-off-by: Arınç ÜNAL <arinc.unal@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/dsa/mt7530.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/drivers/net/dsa/mt7530.c +++ b/drivers/net/dsa/mt7530.c @@ -2471,8 +2471,6 @@ mt7530_setup(struct dsa_switch *ds) SYS_CTRL_PHY_RST | SYS_CTRL_SW_RST | SYS_CTRL_REG_RST); - mt7530_pll_setup(priv); - /* Lower Tx driving for TRGMII path */ for (i = 0; i < NUM_TRGMII_CTRL; i++) mt7530_write(priv, MT7530_TRGMII_TD_ODT(i), @@ -2490,6 +2488,9 @@ mt7530_setup(struct dsa_switch *ds) priv->p6_interface = PHY_INTERFACE_MODE_NA; + if ((val & HWTRAP_XTAL_MASK) == HWTRAP_XTAL_40MHZ) + mt7530_pll_setup(priv); + mt753x_trap_frames(priv); /* Enable and reset MIB counters */
