Re: [PATCH v2] HID: intel-ish-hid: ipc: Rework EHL OOB wakeup

[srinivas pandruvada <srinivas.pandruvada@linux.intel.com>]

Hi Kai,

Sorry for he delay in getting back on this. I have a question below:

On Wed, 2023-11-08 at 14:19 +0200, Kai-Heng Feng wrote:
> Since PCI core and ACPI core already handles PCI PME wake and GPE
> wake
> when the device has wakeup capability, use device_init_wakeup() to
> let
> them do the wakeup setting work.
> 
> Also add a shutdown callback which uses pci_prepare_to_sleep() to let
> PCI and ACPI set OOB wakeup for S5.
> 
> Cc: Jian Hui Lee <jianhui.lee@canonical.com>
> Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
> ---
> v2:
>  Rebase on ("HID: intel-ish-hid: ipc: Disable and reenable ACPI GPE
> bit")
> 
>  drivers/hid/intel-ish-hid/ipc/pci-ish.c | 67 ++++++-----------------
> --
>  1 file changed, 15 insertions(+), 52 deletions(-)
> 
> diff --git a/drivers/hid/intel-ish-hid/ipc/pci-ish.c
> b/drivers/hid/intel-ish-hid/ipc/pci-ish.c
> index 710fda5f19e1..65e7eeb2fa64 100644
> --- a/drivers/hid/intel-ish-hid/ipc/pci-ish.c
> +++ b/drivers/hid/intel-ish-hid/ipc/pci-ish.c
> @@ -119,50 +119,6 @@ static inline bool ish_should_leave_d0i3(struct
> pci_dev *pdev)
>         return !pm_resume_via_firmware() || pdev->device ==
> CHV_DEVICE_ID;
>  }
>  
> -static int enable_gpe(struct device *dev)
> -{
> -#ifdef CONFIG_ACPI
> -       acpi_status acpi_sts;
> -       struct acpi_device *adev;
> -       struct acpi_device_wakeup *wakeup;
> -
> -       adev = ACPI_COMPANION(dev);
> -       if (!adev) {
> -               dev_err(dev, "get acpi handle failed\n");
> -               return -ENODEV;
> -       }
> -       wakeup = &adev->wakeup;
> -
> -       /*
> -        * Call acpi_disable_gpe(), so that reference count
> -        * gpe_event_info->runtime_count doesn't overflow.
> -        * When gpe_event_info->runtime_count = 0, the call
> -        * to acpi_disable_gpe() simply return.
> -        */
> -       acpi_disable_gpe(wakeup->gpe_device, wakeup->gpe_number);
> -
> -       acpi_sts = acpi_enable_gpe(wakeup->gpe_device, wakeup-
> >gpe_number);
> -       if (ACPI_FAILURE(acpi_sts)) {
> -               dev_err(dev, "enable ose_gpe failed\n");
> -               return -EIO;
> -       }
> -
> -       return 0;
> -#else
> -       return -ENODEV;
> -#endif
> -}
> -
> -static void enable_pme_wake(struct pci_dev *pdev)
> -{
> -       if ((pci_pme_capable(pdev, PCI_D0) ||
> -            pci_pme_capable(pdev, PCI_D3hot) ||
> -            pci_pme_capable(pdev, PCI_D3cold)) && !enable_gpe(&pdev-
> >dev)) {
> -               pci_pme_active(pdev, true);
> -               dev_dbg(&pdev->dev, "ish ipc driver pme wake
> enabled\n");
> -       }
> -}
> -
>  /**
>   * ish_probe() - PCI driver probe callback
>   * @pdev:      pci device
> @@ -233,7 +189,7 @@ static int ish_probe(struct pci_dev *pdev, const
> struct pci_device_id *ent)
>  
>         /* Enable PME for EHL */
>         if (pdev->device == EHL_Ax_DEVICE_ID)
> -               enable_pme_wake(pdev);
> +               device_init_wakeup(dev, true);

For apple to apple comparison, which path will call
https://elixir.bootlin.com/linux/latest/C/ident/__pci_enable_wake
which will call pci_pme_active()?

Thanks,
Srinivas

>  
>         ret = ish_init(ishtp);
>         if (ret)
> @@ -256,6 +212,19 @@ static void ish_remove(struct pci_dev *pdev)
>         ish_device_disable(ishtp_dev);
>  }
>  
> +
> +/**
> + * ish_shutdown() - PCI driver shutdown callback
> + * @pdev:      pci device
> + *
> + * This function sets up wakeup for S5
> + */
> +static void ish_shutdown(struct pci_dev *pdev)
> +{
> +       if (pdev->device == EHL_Ax_DEVICE_ID)
> +               pci_prepare_to_sleep(pdev);
> +}
> +
>  static struct device __maybe_unused *ish_resume_device;
>  
>  /* 50ms to get resume response */
> @@ -378,13 +347,6 @@ static int __maybe_unused ish_resume(struct
> device *device)
>         struct pci_dev *pdev = to_pci_dev(device);
>         struct ishtp_device *dev = pci_get_drvdata(pdev);
>  
> -       /* add this to finish power flow for EHL */
> -       if (dev->pdev->device == EHL_Ax_DEVICE_ID) {
> -               pci_set_power_state(pdev, PCI_D0);
> -               enable_pme_wake(pdev);
> -               dev_dbg(dev->devc, "set power state to D0 for
> ehl\n");
> -       }
> -
>         ish_resume_device = device;
>         dev->resume_flag = 1;
>  
> @@ -400,6 +362,7 @@ static struct pci_driver ish_driver = {
>         .id_table = ish_pci_tbl,
>         .probe = ish_probe,
>         .remove = ish_remove,
> +       .shutdown = ish_shutdown,
>         .driver.pm = &ish_pm_ops,
>  };
>