RE: [PATCH net-next 1/1] r8169: enable RTL8125 ASPM L1.2

[Hau]

> 
> On 26.01.2022 16:03, Hau wrote:
> >
> >
> >> -----Original Message-----
> >> From: Heiner Kallweit [mailto:hkallweit1@xxxxxxxxx]
> >> Sent: Wednesday, January 26, 2022 9:47 PM
> >> To: Hau <hau@xxxxxxxxxxx>; netdev@xxxxxxxxxxxxxxx
> >> Cc: nic_swsd <nic_swsd@xxxxxxxxxxx>; linux-kernel@xxxxxxxxxxxxxxx
> >> Subject: Re: [PATCH net-next 1/1] r8169: enable RTL8125 ASPM L1.2
> >>
> >> On 26.01.2022 14:00, Hau wrote:
> >>>> On 24.01.2022 19:19, Chunhao Lin wrote:
> >>>>> This patch will enable RTL8125 ASPM L1.2 on the platforms that
> >>>>> have tested RTL8125 with ASPM L1.2 enabled.
> >>>>> Register mac ocp 0xc0b2 will help to identify if RTL8125 has been
> >>>>> tested on L1.2 enabled platform. If it is, this register will be set to 0xf.
> >>>>> If not, this register will be default value 0.
> >>>>>
> >>>>> Signed-off-by: Chunhao Lin <hau@xxxxxxxxxxx>
> >>>>> ---
> >>>>>  drivers/net/ethernet/realtek/r8169_main.c | 99
> >>>>> ++++++++++++++++++-----
> >>>>>  1 file changed, 79 insertions(+), 20 deletions(-)
> >>>>>
> >>>>> diff --git a/drivers/net/ethernet/realtek/r8169_main.c
> >>>>> b/drivers/net/ethernet/realtek/r8169_main.c
> >>>>> index 19e2621e0645..b1e013969d4c 100644
> >>>>> --- a/drivers/net/ethernet/realtek/r8169_main.c
> >>>>> +++ b/drivers/net/ethernet/realtek/r8169_main.c
> >>>>> @@ -2238,21 +2238,6 @@ static void rtl_wol_enable_rx(struct
> >>>> rtl8169_private *tp)
> >>>>>  			AcceptBroadcast | AcceptMulticast |
> >>>> AcceptMyPhys);  }
> >>>>>
> >>>>> -static void rtl_prepare_power_down(struct rtl8169_private *tp) -{
> >>>>> -	if (tp->dash_type != RTL_DASH_NONE)
> >>>>> -		return;
> >>>>> -
> >>>>> -	if (tp->mac_version == RTL_GIGA_MAC_VER_32 ||
> >>>>> -	    tp->mac_version == RTL_GIGA_MAC_VER_33)
> >>>>> -		rtl_ephy_write(tp, 0x19, 0xff64);
> >>>>> -
> >>>>> -	if (device_may_wakeup(tp_to_dev(tp))) {
> >>>>> -		phy_speed_down(tp->phydev, false);
> >>>>> -		rtl_wol_enable_rx(tp);
> >>>>> -	}
> >>>>> -}
> >>>>> -
> >>>>>  static void rtl_init_rxcfg(struct rtl8169_private *tp)  {
> >>>>>  	switch (tp->mac_version) {
> >>>>> @@ -2650,6 +2635,34 @@ static void
> >>>>> rtl_pcie_state_l2l3_disable(struct
> >>>> rtl8169_private *tp)
> >>>>>  	RTL_W8(tp, Config3, RTL_R8(tp, Config3) & ~Rdy_to_L23);  }
> >>>>>
> >>>>> +static void rtl_disable_exit_l1(struct rtl8169_private *tp) {
> >>>>> +	/* Bits control which events trigger ASPM L1 exit:
> >>>>> +	 * Bit 12: rxdv
> >>>>> +	 * Bit 11: ltr_msg
> >>>>> +	 * Bit 10: txdma_poll
> >>>>> +	 * Bit  9: xadm
> >>>>> +	 * Bit  8: pktavi
> >>>>> +	 * Bit  7: txpla
> >>>>> +	 */
> >>>>> +	switch (tp->mac_version) {
> >>>>> +	case RTL_GIGA_MAC_VER_34 ... RTL_GIGA_MAC_VER_36:
> >>>>> +		rtl_eri_clear_bits(tp, 0xd4, 0x1f00);
> >>>>> +		break;
> >>>>> +	case RTL_GIGA_MAC_VER_37 ... RTL_GIGA_MAC_VER_38:
> >>>>> +		rtl_eri_clear_bits(tp, 0xd4, 0x0c00);
> >>>>> +		break;
> >>>>> +	case RTL_GIGA_MAC_VER_40 ... RTL_GIGA_MAC_VER_53:
> >>>>> +		rtl_eri_clear_bits(tp, 0xd4, 0x1f80);
> >>>>> +		break;
> >>>>> +	case RTL_GIGA_MAC_VER_60 ... RTL_GIGA_MAC_VER_63:
> >>>>> +		r8168_mac_ocp_modify(tp, 0xc0ac, 0x1f80, 0);
> >>>>> +		break;
> >>>>> +	default:
> >>>>> +		break;
> >>>>> +	}
> >>>>> +}
> >>>>> +
> >>>>>  static void rtl_enable_exit_l1(struct rtl8169_private *tp)  {
> >>>>>  	/* Bits control which events trigger ASPM L1 exit:
> >>>>> @@ -2692,6 +2705,33 @@ static void
> >>>>> rtl_hw_aspm_clkreq_enable(struct
> >>>> rtl8169_private *tp, bool enable)
> >>>>>  	udelay(10);
> >>>>>  }
> >>>>>
> >>>>> +static void rtl_hw_aspm_l12_enable(struct rtl8169_private *tp,
> >>>>> +bool
> >>>>> +enable) {
> >>>>> +	/* Don't enable L1.2 in the chip if OS can't control ASPM */
> >>>>> +	if (enable && tp->aspm_manageable) {
> >>>>> +		r8168_mac_ocp_modify(tp, 0xe094, 0xff00, 0);
> >>>>> +		r8168_mac_ocp_modify(tp, 0xe092, 0x00ff, BIT(2));
> >>>>> +	} else {
> >>>>> +		r8168_mac_ocp_modify(tp, 0xe092, 0x00ff, 0);
> >>>>> +	}
> >>>>> +}
> >>>>> +
> >>>>> +static void rtl_prepare_power_down(struct rtl8169_private *tp) {
> >>>>> +	if (tp->dash_type != RTL_DASH_NONE)
> >>>>> +		return;
> >>>>> +
> >>>>> +	if (tp->mac_version == RTL_GIGA_MAC_VER_32 ||
> >>>>> +	    tp->mac_version == RTL_GIGA_MAC_VER_33)
> >>>>> +		rtl_ephy_write(tp, 0x19, 0xff64);
> >>>>> +
> >>>>> +	if (device_may_wakeup(tp_to_dev(tp))) {
> >>>>> +		rtl_disable_exit_l1(tp);
> >>>>> +		phy_speed_down(tp->phydev, false);
> >>>>> +		rtl_wol_enable_rx(tp);
> >>>>> +	}
> >>>>> +}
> >>>>> +
> >>>>>  static void rtl_set_fifo_size(struct rtl8169_private *tp, u16 rx_stat,
> >>>>>  			      u16 tx_stat, u16 rx_dyn, u16 tx_dyn)  { @@ -
> >>>> 3675,6 +3715,7
> >>>>> @@ static void rtl_hw_start_8125b(struct rtl8169_private *tp)
> >>>>>  	rtl_ephy_init(tp, e_info_8125b);
> >>>>>  	rtl_hw_start_8125_common(tp);
> >>>>>
> >>>>> +	rtl_hw_aspm_l12_enable(tp, true);
> >>>>>  	rtl_hw_aspm_clkreq_enable(tp, true);  }
> >>>>>
> >>>>> @@ -5255,6 +5296,20 @@ static void rtl_init_mac_address(struct
> >>>> rtl8169_private *tp)
> >>>>>  	rtl_rar_set(tp, mac_addr);
> >>>>>  }
> >>>>>
> >>>>> +/* mac ocp 0xc0b2 will help to identify if RTL8125 has been
> >>>>> +tested
> >>>>> + * on L1.2 enabled platform. If it is, this register will be set to 0xf.
> >>>>> + * If not, this register will be default value 0.
> >>>>> + */
> >>>>> +static bool rtl_platform_l12_enabled(struct rtl8169_private *tp) {
> >>>>> +	switch (tp->mac_version) {
> >>>>> +	case RTL_GIGA_MAC_VER_60 ... RTL_GIGA_MAC_VER_63:
> >>>>> +		return (r8168_mac_ocp_read(tp, 0xc0b2) & 0xf) ?
> true : false;
> >>>>> +	default:
> >>>>> +		return false;
> >>>>> +	}
> >>>>> +}
> >>>>> +
> >>>>>  static int rtl_init_one(struct pci_dev *pdev, const struct
> >>>>> pci_device_id *ent)  {
> >>>>>  	struct rtl8169_private *tp;
> >>>>> @@ -5333,11 +5388,15 @@ static int rtl_init_one(struct pci_dev
> >>>>> *pdev,
> >>>> const struct pci_device_id *ent)
> >>>>>  	 * Chips from RTL8168h partially have issues with L1.2, but seem
> >>>>>  	 * to work fine with L1 and L1.1.
> >>>>>  	 */
> >>>>> -	if (tp->mac_version >= RTL_GIGA_MAC_VER_45)
> >>>>> -		rc = pci_disable_link_state(pdev, PCIE_LINK_STATE_L1_2);
> >>>>> -	else
> >>>>> -		rc = pci_disable_link_state(pdev, PCIE_LINK_STATE_L1);
> >>>>> -	tp->aspm_manageable = !rc;
> >>>>> +	if (!rtl_platform_l12_enabled(tp)) {
> >>>>> +		if (tp->mac_version >= RTL_GIGA_MAC_VER_45)
> >>>>> +			rc = pci_disable_link_state(pdev,
> >>>> PCIE_LINK_STATE_L1_2);
> >>>>> +		else
> >>>>> +			rc = pci_disable_link_state(pdev,
> >>>> PCIE_LINK_STATE_L1);
> >>>>> +		tp->aspm_manageable = !rc;
> >>>>> +	} else {
> >>>>> +		tp->aspm_manageable = pcie_aspm_enabled(pdev);
> >>>>> +	}
> >>>>>
> >>>>>  	tp->dash_type = rtl_check_dash(tp);
> >>>>>
> >>>>
> >>>> Hi Hau,
> >>>>
> >>>> the following is a stripped-down version of the patch. Could you
> >>>> please check/test?
> >>> This patch is ok.
> >>> L1 substate lock can apply for both rtl8125a.rtl8125b.
> >>> if (enable && tp->aspm_manageable) {
> >>> 	RTL_W8(tp, Config5, RTL_R8(tp, Config5) | ASPM_en);
> >>> 	RTL_W8(tp, Config2, RTL_R8(tp, Config2) | ClkReqEn);
> >>>
> >>> 	if (tp->mac_version >= RTL_GIGA_MAC_VER_60) {
> >>> 		r8168_mac_ocp_modify(tp, 0xe094, 0xff00, 0);
> >>> 		r8168_mac_ocp_modify(tp, 0xe092, 0x00ff, BIT(2));
> >>> 	}
> >>> } else {
> >>> 	if (tp->mac_version >= RTL_GIGA_MAC_VER_60)
> >>> 		r8168_mac_ocp_modify(tp, 0xe092, 0x00ff, 0);
> >>>
> >>> 	RTL_W8(tp, Config2, RTL_R8(tp, Config2) & ~ClkReqEn);
> >>> 	RTL_W8(tp, Config5, RTL_R8(tp, Config5) & ~ASPM_en); }
> >>>
> >>>> If function rtl_disable_exit_l1() is actually needed, I'd prefer to
> >>>> add it in a separate patch (to facilitate bisecting).
> >>>>
> >>> If exit l1 mask is enabled, hardware will prone to exit l1. That
> >>> will prevent hardware from entering l1 substate. So It needs to
> >>> disable l1 exist mask when device go to d3 state for entering l1 substate..
> >>>
> >> My understanding of PCI power management may be incomplete, but:
> >> If a device goes to D3, then doesn't the bus go to L2/L3?
> >> L1 exit criteria would be irrelevant then.
> > Your understanding is correct.
> > D3 is divided to two substate, D3hot and D3cold. D3cold will enter L2/L3.
> > D3hot may enter L1 or L2/L3 ready.  In D3hot case, enable exit l1 mask
> > will prevent hardware from entering PM L1. That is our hardware issue.
> > So we disable exit l1 mask before hardware enter D3.
> >
> 
> Thanks! One, hopefully last, question:
> Are you aware of any boards/systems setting this "L1.2 was tested and is
> safe" flag?
> Then this could be mentioned in the commit description.
Google chromebox will be the first one to use this flag.

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