[Intel-wired-lan] [PATCH iwl-net v2 1/1] e1000e: reconfigure PLL clock gate value and re-enable K1 on Meteor Lake

[Timo Teras]

Hi

This seems to retrigger the malfunction on a Dell Pro 16 Plus PB16250 laptop.

CPU Interl Core Ultra 5 235U
CPU family 6 model 181 stepping 0

Please advise if you can reproduce or suggest alternative fix?

Thanks,
Timo

On Mon,  2 Feb 2026 12:32:57 +0200
Vitaly Lifshits <vitaly.lifshits at intel.com> wrote:

> Commit 3c7bf5af21960 ("e1000e: Introduce private flag to disable K1")
> disabled K1 by default on Meteor Lake and newer systems due to packet
> loss observed on various platforms. However, disabling K1 caused an
> increase in power consumption due to blocking PC10 state.
> 
> To mitigate this, reconfigure the PLL clock gate value so that K1 can
> remain enabled without incurring the additional power consumption.
> 
> Link: https://bugzilla.kernel.org/show_bug.cgi?id=220954
> Fixes: 3c7bf5af21960 ("e1000e: Introduce private flag to disable K1")
> Signed-off-by: Vitaly Lifshits <vitaly.lifshits at intel.com>
> ---
> v2: add comment for the PLL timeout value and revisit the commit message
> v1: initial version
> ---
>  drivers/net/ethernet/intel/e1000e/ich8lan.c | 6 ++++++
>  drivers/net/ethernet/intel/e1000e/netdev.c  | 3 ---
>  2 files changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/net/ethernet/intel/e1000e/ich8lan.c b/drivers/net/ethernet/intel/e1000e/ich8lan.c
> index 13841daba399..8e88aa9048da 100644
> --- a/drivers/net/ethernet/intel/e1000e/ich8lan.c
> +++ b/drivers/net/ethernet/intel/e1000e/ich8lan.c
> @@ -1594,6 +1594,12 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw)
>  			phy_reg &= ~I217_PLL_CLOCK_GATE_MASK;
>  			if (speed == SPEED_100 || speed == SPEED_10)
>  				phy_reg |= 0x3E8;
> +			else if (hw->mac.type == e1000_pch_mtp ||
> +				 hw->mac.type == e1000_pch_ptp)
> +				/* Increase PLL clock gate timeout to avoid
> +				 * packet loss
> +				 */
> +				phy_reg |= 0x1D5;
>  			else
>  				phy_reg |= 0xFA;
>  			e1e_wphy_locked(hw, I217_PLL_CLOCK_GATE_REG, phy_reg);
> diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
> index 82d1d5fe51d5..8f0eb822610b 100644
> --- a/drivers/net/ethernet/intel/e1000e/netdev.c
> +++ b/drivers/net/ethernet/intel/e1000e/netdev.c
> @@ -7755,9 +7755,6 @@ static int e1000_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
>  	/* init PTP hardware clock */
>  	e1000e_ptp_init(adapter);
>  
> -	if (hw->mac.type >= e1000_pch_mtp)
> -		adapter->flags2 |= FLAG2_DISABLE_K1;
> -
>  	/* reset the hardware with the new settings */
>  	e1000e_reset(adapter);
>