Re: [PATCH] PCI: r8169: add suspend/resume aspm quirk

[Bjorn Helgaas <helgaas@kernel.org>]

[+cc r8169 folks]

On Mon, Jul 08, 2024 at 03:38:15PM +0000, George-Daniel Matei wrote:
> Added aspm suspend/resume hooks that run
> before and after suspend and resume to change
> the ASPM states of the PCI bus in order to allow
> the system suspend while trying to prevent card hangs

Why is this needed?  Is there a r8169 defect we're working around?
A BIOS defect?  Is there a problem report you can reference here?

s/Added/Add/

s/aspm/ASPM/ above

s/PCI bus/device and parent/

Add period at end of sentence.

Rewrap to fill 75 columns.

> Signed-off-by: George-Daniel Matei <danielgeorgem@chromium.org>
> ---
>  drivers/pci/quirks.c | 142 +++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 142 insertions(+)
> 
> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
> index dc12d4a06e21..aa3dba2211d3 100644
> --- a/drivers/pci/quirks.c
> +++ b/drivers/pci/quirks.c
> @@ -6189,6 +6189,148 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x56b0, aspm_l1_acceptable_latency
>  DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x56b1, aspm_l1_acceptable_latency);
>  DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x56c0, aspm_l1_acceptable_latency);
>  DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x56c1, aspm_l1_acceptable_latency);
> +
> +static const struct dmi_system_id chromebox_match_table[] = {
> +	{
> +		.matches = {
> +			DMI_MATCH(DMI_PRODUCT_NAME, "Brask"),
> +			DMI_MATCH(DMI_BIOS_VENDOR, "coreboot"),
> +		}
> +	},
> +	{
> +		.matches = {
> +			DMI_MATCH(DMI_PRODUCT_NAME, "Aurash"),
> +			DMI_MATCH(DMI_BIOS_VENDOR, "coreboot"),
> +		}
> +	},
> +		{
> +		.matches = {
> +			DMI_MATCH(DMI_PRODUCT_NAME, "Bujia"),
> +			DMI_MATCH(DMI_BIOS_VENDOR, "coreboot"),
> +		}
> +	},
> +	{
> +		.matches = {
> +			DMI_MATCH(DMI_PRODUCT_NAME, "Gaelin"),
> +			DMI_MATCH(DMI_BIOS_VENDOR, "coreboot"),
> +		}
> +	},
> +	{
> +		.matches = {
> +			DMI_MATCH(DMI_PRODUCT_NAME, "Gladios"),
> +			DMI_MATCH(DMI_BIOS_VENDOR, "coreboot"),
> +		}
> +	},
> +	{
> +		.matches = {
> +			DMI_MATCH(DMI_PRODUCT_NAME, "Hahn"),
> +			DMI_MATCH(DMI_BIOS_VENDOR, "coreboot"),
> +		}
> +	},
> +	{
> +		.matches = {
> +			DMI_MATCH(DMI_PRODUCT_NAME, "Jeev"),
> +			DMI_MATCH(DMI_BIOS_VENDOR, "coreboot"),
> +		}
> +	},
> +	{
> +		.matches = {
> +			DMI_MATCH(DMI_PRODUCT_NAME, "Kinox"),
> +			DMI_MATCH(DMI_BIOS_VENDOR, "coreboot"),
> +		}
> +	},
> +	{
> +		.matches = {
> +			DMI_MATCH(DMI_PRODUCT_NAME, "Kuldax"),
> +			DMI_MATCH(DMI_BIOS_VENDOR, "coreboot"),
> +		}
> +	},
> +	{
> +		.matches = {
> +			DMI_MATCH(DMI_PRODUCT_NAME, "Lisbon"),
> +			DMI_MATCH(DMI_BIOS_VENDOR, "coreboot"),
> +		}
> +	},
> +	{
> +			.matches = {
> +			DMI_MATCH(DMI_PRODUCT_NAME, "Moli"),
> +			DMI_MATCH(DMI_BIOS_VENDOR, "coreboot"),
> +		}
> +	},
> +	{ }
> +};
> +
> +static void rtl8169_suspend_aspm_settings(struct pci_dev *dev)
> +{
> +	u16 val = 0;
> +
> +	if (dmi_check_system(chromebox_match_table)) {
> +		//configure parent
> +		pcie_capability_clear_and_set_word(dev->bus->self,
> +						   PCI_EXP_LNKCTL,
> +						   PCI_EXP_LNKCTL_ASPMC,
> +						   PCI_EXP_LNKCTL_ASPM_L1);
> +
> +		pci_read_config_word(dev->bus->self,
> +				     dev->bus->self->l1ss + PCI_L1SS_CTL1,
> +				     &val);
> +		val = (val & ~PCI_L1SS_CTL1_L1SS_MASK) |
> +		      PCI_L1SS_CTL1_PCIPM_L1_2 | PCI_L1SS_CTL1_PCIPM_L1_2 |
> +		      PCI_L1SS_CTL1_ASPM_L1_1;
> +		pci_write_config_word(dev->bus->self,
> +				      dev->bus->self->l1ss + PCI_L1SS_CTL1,
> +				      val);
> +
> +		//configure device
> +		pcie_capability_clear_and_set_word(dev, PCI_EXP_LNKCTL,
> +						   PCI_EXP_LNKCTL_ASPMC,
> +						   PCI_EXP_LNKCTL_ASPM_L1);
> +
> +		pci_read_config_word(dev, dev->l1ss + PCI_L1SS_CTL1, &val);
> +		val = (val & ~PCI_L1SS_CTL1_L1SS_MASK) |
> +		      PCI_L1SS_CTL1_PCIPM_L1_2 | PCI_L1SS_CTL1_PCIPM_L1_2 |
> +		      PCI_L1SS_CTL1_ASPM_L1_1;
> +		pci_write_config_word(dev, dev->l1ss + PCI_L1SS_CTL1, val);
> +	}
> +}
> +
> +DECLARE_PCI_FIXUP_SUSPEND(PCI_VENDOR_ID_REALTEK, 0x8168,
> +			  rtl8169_suspend_aspm_settings);
> +
> +static void rtl8169_resume_aspm_settings(struct pci_dev *dev)
> +{
> +	u16 val = 0;
> +
> +	if (dmi_check_system(chromebox_match_table)) {
> +		//configure device
> +		pcie_capability_clear_and_set_word(dev, PCI_EXP_LNKCTL,
> +						   PCI_EXP_LNKCTL_ASPMC, 0);
> +
> +		pci_read_config_word(dev->bus->self,
> +				     dev->bus->self->l1ss + PCI_L1SS_CTL1,
> +				     &val);
> +		val = val & ~PCI_L1SS_CTL1_L1SS_MASK;
> +		pci_write_config_word(dev->bus->self,
> +				      dev->bus->self->l1ss + PCI_L1SS_CTL1,
> +				      val);
> +
> +		//configure parent
> +		pcie_capability_clear_and_set_word(dev->bus->self,
> +						   PCI_EXP_LNKCTL,
> +						   PCI_EXP_LNKCTL_ASPMC, 0);
> +
> +		pci_read_config_word(dev->bus->self,
> +				     dev->bus->self->l1ss + PCI_L1SS_CTL1,
> +				     &val);
> +		val = val & ~PCI_L1SS_CTL1_L1SS_MASK;
> +		pci_write_config_word(dev->bus->self,
> +				      dev->bus->self->l1ss + PCI_L1SS_CTL1,
> +				      val);

Updates the parent (dev->bus->self) twice; was the first one supposed
to update the device (dev)?

This doesn't restore the state as it existed before suspend.  Does
this rely on other parts of restore to do that?

> +	}
> +}
> +
> +DECLARE_PCI_FIXUP_RESUME(PCI_VENDOR_ID_REALTEK, 0x8168,
> +			 rtl8169_resume_aspm_settings);
>  #endif
>  
>  #ifdef CONFIG_PCIE_DPC
> -- 
> 2.45.2.803.g4e1b14247a-goog
>