Re: [PATCH net-next 3/3] r8169: disable RTL8126 ZRX-DC timeout

[Bjorn Helgaas]

On Fri, Feb 21, 2025 at 03:18:28PM +0800, ChunHao Lin wrote:
> 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.

s/dose/does/

Is ZRX-DC a PCIe spec?  A Google search suggests that it might not be
completely Realtek-specific?

> +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)

Is this a standard PCIe extended capability?  If so, it would be nice
to search for it with pci_find_ext_capability() and use standard
#defines.

Bjorn