Messages in this thread | | | Date | Mon, 24 Jan 2022 21:57:37 +0100 | From | Heiner Kallweit <> | Subject | Re: [PATCH net-next 1/1] r8169: enable RTL8125 ASPM L1.2 |
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Hi Hau,
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. > Who and what defines which value this register has? The BIOS? ACPI? Mainboard vendors test and can control the flagging? How about add-on cards and systems with other boot loaders, e.g. SBC's with RTL8125 like Odroid H2+?
What is actually the critical component that makes L1.2 work or not with RTL8125 on a particular system? The chipset? Or electrical characteristics?
The difference in power consumption between L1.1 and L1.2 is a few mW ([0]). So I wonder whether it's worth it to add this flagging mechanism. Or does it also impact reaching certain package power saving states?
[0] https://pcisig.com/making-most-pcie%C2%AE-low-power-features
> Signed-off-by: Chunhao Lin <hau@realtek.com> > --- > 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) > +{
Why is this function needed? The chip should be quiet anyway. IOW: What could be the impact of not having this function currently? If it fixes something then it should be a separate patch.
> + /* 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) > +{
I assume this code works on RTL8125 only. Then this should be reflected in the function naming, like we do it for other version-specific functions.
> + /* 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) > +{
The function name is misleading. It could be read as checking whether the platform supports L1.2.
> + 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); > + } >
Better readable may be the following:
if (rtl_platform_l12_enabled(tp)) { tp->aspm_manageable = pcie_aspm_enabled(pdev); } else if (tp->mac_version >= RTL_GIGA_MAC_VER_45) { rc = pci_disable_link_state(pdev, PCIE_LINK_STATE_L1_2); tp->aspm_manageable = !rc; } else { rc = pci_disable_link_state(pdev, PCIE_LINK_STATE_L1); tp->aspm_manageable = !rc; }
> tp->dash_type = rtl_check_dash(tp); >
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