Disable it due to it dose not meet ZRX-DC specification. If it is enabled,
device will exit L1 substate every 100ms. Disable it for saving more power
in L1 substate.

Signed-off-by: ChunHao Lin <hau@realtek.com>
---
 drivers/net/ethernet/realtek/r8169_main.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/drivers/net/ethernet/realtek/r8169_main.c b/drivers/net/ethernet/realtek/r8169_main.c
index 3c663fca07d3..dfc96b09b85e 100644
--- a/drivers/net/ethernet/realtek/r8169_main.c
+++ b/drivers/net/ethernet/realtek/r8169_main.c
@@ -2852,6 +2852,21 @@ static u32 rtl_csi_read(struct rtl8169_private *tp, int addr)
 		RTL_R32(tp, CSIDR) : ~0;
 }
 
+static void rtl_disable_zrxdc_timeout(struct rtl8169_private *tp)
+{
+	struct pci_dev *pdev = tp->pci_dev;
+	u8 val;
+
+	if (pdev->cfg_size > 0x0890 &&
+	    pci_read_config_byte(pdev, 0x0890, &val) == PCIBIOS_SUCCESSFUL &&
+	    pci_write_config_byte(pdev, 0x0890, val & ~BIT(0)) == PCIBIOS_SUCCESSFUL)
+		return;
+
+	netdev_notice_once(tp->dev,
+		"No native access to PCI extended config space, falling back to CSI\n");
+	rtl_csi_write(tp, 0x0890, rtl_csi_read(tp, 0x0890) & ~BIT(0));
+}
+
 static void rtl_set_aspm_entry_latency(struct rtl8169_private *tp, u8 val)
 {
 	struct pci_dev *pdev = tp->pci_dev;
@@ -3824,6 +3839,7 @@ static void rtl_hw_start_8125d(struct rtl8169_private *tp)
 
 static void rtl_hw_start_8126a(struct rtl8169_private *tp)
 {
+	rtl_disable_zrxdc_timeout(tp);
 	rtl_set_def_aspm_entry_latency(tp);
 	rtl_hw_start_8125_common(tp);
 }
-- 
2.43.0

On 14.03.2025 08:50, ChunHao Lin wrote:
> Disable it due to it dose not meet ZRX-DC specification. If it is enabled,

dose -> does

> device will exit L1 substate every 100ms. Disable it for saving more power
> in L1 substate.
> 
> Signed-off-by: ChunHao Lin <hau@realtek.com>
> ---
>  drivers/net/ethernet/realtek/r8169_main.c | 16 ++++++++++++++++
>  1 file changed, 16 insertions(+)
> 
> diff --git a/drivers/net/ethernet/realtek/r8169_main.c b/drivers/net/ethernet/realtek/r8169_main.c
> index 3c663fca07d3..dfc96b09b85e 100644
> --- a/drivers/net/ethernet/realtek/r8169_main.c
> +++ b/drivers/net/ethernet/realtek/r8169_main.c
> @@ -2852,6 +2852,21 @@ static u32 rtl_csi_read(struct rtl8169_private *tp, int addr)
>  		RTL_R32(tp, CSIDR) : ~0;
>  }
>  
> +static void rtl_disable_zrxdc_timeout(struct rtl8169_private *tp)
> +{
> +	struct pci_dev *pdev = tp->pci_dev;
> +	u8 val;
> +
> +	if (pdev->cfg_size > 0x0890 &&
> +	    pci_read_config_byte(pdev, 0x0890, &val) == PCIBIOS_SUCCESSFUL &&
> +	    pci_write_config_byte(pdev, 0x0890, val & ~BIT(0)) == PCIBIOS_SUCCESSFUL)
> +		return;
> +
> +	netdev_notice_once(tp->dev,
> +		"No native access to PCI extended config space, falling back to CSI\n");
> +	rtl_csi_write(tp, 0x0890, rtl_csi_read(tp, 0x0890) & ~BIT(0));
> +}
> +

Does the datasheet have a name for this extended config space register and bit 0?
This would be better than using magic numbers.

I think we can factor out the extended config space access to a helper. The same code
we have in another place already. But this can be done as a follow-up.

>  static void rtl_set_aspm_entry_latency(struct rtl8169_private *tp, u8 val)
>  {
>  	struct pci_dev *pdev = tp->pci_dev;
> @@ -3824,6 +3839,7 @@ static void rtl_hw_start_8125d(struct rtl8169_private *tp)
>  
>  static void rtl_hw_start_8126a(struct rtl8169_private *tp)
>  {
> +	rtl_disable_zrxdc_timeout(tp);
>  	rtl_set_def_aspm_entry_latency(tp);
>  	rtl_hw_start_8125_common(tp);
>  }

> External mail : This email originated from outside the organization. Do not
> reply, click links, or open attachments unless you recognize the sender and
> know the content is safe.
> 
> 
> 
> On 14.03.2025 08:50, ChunHao Lin wrote:
> > Disable it due to it dose not meet ZRX-DC specification. If it is
> > enabled,
> 
> dose -> does
> 
> > device will exit L1 substate every 100ms. Disable it for saving more
> > power in L1 substate.
> >
> > Signed-off-by: ChunHao Lin <hau@realtek.com>
> > ---
> >  drivers/net/ethernet/realtek/r8169_main.c | 16 ++++++++++++++++
> >  1 file changed, 16 insertions(+)
> >
> > diff --git a/drivers/net/ethernet/realtek/r8169_main.c
> > b/drivers/net/ethernet/realtek/r8169_main.c
> > index 3c663fca07d3..dfc96b09b85e 100644
> > --- a/drivers/net/ethernet/realtek/r8169_main.c
> > +++ b/drivers/net/ethernet/realtek/r8169_main.c
> > @@ -2852,6 +2852,21 @@ static u32 rtl_csi_read(struct rtl8169_private *tp,
> int addr)
> >               RTL_R32(tp, CSIDR) : ~0;  }
> >
> > +static void rtl_disable_zrxdc_timeout(struct rtl8169_private *tp) {
> > +     struct pci_dev *pdev = tp->pci_dev;
> > +     u8 val;
> > +
> > +     if (pdev->cfg_size > 0x0890 &&
> > +         pci_read_config_byte(pdev, 0x0890, &val) == PCIBIOS_SUCCESSFUL
> &&
> > +         pci_write_config_byte(pdev, 0x0890, val & ~BIT(0)) ==
> PCIBIOS_SUCCESSFUL)
> > +             return;
> > +
> > +     netdev_notice_once(tp->dev,
> > +             "No native access to PCI extended config space, falling back to
> CSI\n");
> > +     rtl_csi_write(tp, 0x0890, rtl_csi_read(tp, 0x0890) & ~BIT(0)); }
> > +
> 
> Does the datasheet have a name for this extended config space register and
> bit 0?
> This would be better than using magic numbers.

I will try to get the name of this bit.

> I think we can factor out the extended config space access to a helper. The
> same code we have in another place already. But this can be done as a
> follow-up.
> 
> >  static void rtl_set_aspm_entry_latency(struct rtl8169_private *tp, u8
> > val)  {
> >       struct pci_dev *pdev = tp->pci_dev; @@ -3824,6 +3839,7 @@ static
> > void rtl_hw_start_8125d(struct rtl8169_private *tp)
> >
> >  static void rtl_hw_start_8126a(struct rtl8169_private *tp)  {
> > +     rtl_disable_zrxdc_timeout(tp);
> >       rtl_set_def_aspm_entry_latency(tp);
> >       rtl_hw_start_8125_common(tp);
> >  }