Re: [PATCH] Intel pci device quirk remove D3 delay

[Bjorn Helgaas <bhelgaas@google.com>]

On Tue, Sep 10, 2013 at 04:10:43PM -0700, Todd E Brandt wrote:
> The latest Ivy Bridge Intel chipsets have a hardware optimization which

You said "Ivy Bridge" above but use "Haswell" below.  Let me know if
anything needs to be corrected here.

> allows on-chip PCI devices to ignore the 10ms delay before entering
> or exitting D3 suspend.
> 
> This patch implements the optimization as a pci quirk, since we want
> tight control over which devices use it. This way we can test each device
> individually to be sure there are no issues before we enable the quirk.
> The first set of devices are from the Haswell platform, which includes
> every PCI device that is on the northbridge and southbridge.
> 
> After testing this patch reduces the haswell suspend time from 93 ms to
> 47 ms and resume time from 160 ms to 64 ms. 
> 
> Signed-off-by: Todd Brandt <todd.e.brandt@linux.intel.com>
> 
>  drivers/pci/quirks.c | 23 +++++++++++++++++++++++
>  1 file changed, 23 insertions(+)

I added Rafael's ack and applied this for v3.13 (but I can still make
corrections if required).

Let me know if you want this in v3.12 instead.

Bjorn

> 
> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
> index e85d230..98ea960 100644
> --- a/drivers/pci/quirks.c
> +++ b/drivers/pci/quirks.c
> @@ -2955,6 +2955,29 @@ DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x0102, disable_igfx_irq);
>  DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x010a, disable_igfx_irq);
>  
>  /*
> + * PCI devices which are on Intel chips can skip the 10ms delay
> + * before entering D3 mode.
> + */
> +static void quirk_remove_d3_delay(struct pci_dev *dev)
> +{
> +	dev->d3_delay = 0;
> +}
> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x0c00, quirk_remove_d3_delay);
> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x0412, quirk_remove_d3_delay);
> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x0c0c, quirk_remove_d3_delay);
> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x8c31, quirk_remove_d3_delay);
> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x8c3a, quirk_remove_d3_delay);
> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x8c3d, quirk_remove_d3_delay);
> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x8c2d, quirk_remove_d3_delay);
> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x8c20, quirk_remove_d3_delay);
> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x8c18, quirk_remove_d3_delay);
> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x8c1c, quirk_remove_d3_delay);
> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x8c26, quirk_remove_d3_delay);
> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x8c4e, quirk_remove_d3_delay);
> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x8c02, quirk_remove_d3_delay);
> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x8c22, quirk_remove_d3_delay);
> +
> +/*
>   * Some devices may pass our check in pci_intx_mask_supported if
>   * PCI_COMMAND_INTX_DISABLE works though they actually do not properly
>   * support this feature.
>