Re: [PATCH v2] PCI: Explicitly put devices into D0 when initializing

[Bjorn Helgaas <helgaas@kernel.org>]

On Wed, Apr 23, 2025 at 11:31:32PM -0500, Mario Limonciello wrote:
> From: Mario Limonciello <mario.limonciello@amd.com>
> 
> AMD BIOS team has root caused an issue that NVME storage failed to come
> back from suspend to a lack of a call to _REG when NVME device was probed.
> 
> commit 112a7f9c8edbf ("PCI/ACPI: Call _REG when transitioning D-states")
> added support for calling _REG when transitioning D-states, but this only
> works if the device actually "transitions" D-states.
> 
> commit 967577b062417 ("PCI/PM: Keep runtime PM enabled for unbound PCI
> devices") added support for runtime PM on PCI devices, but never actually
> 'explicitly' sets the device to D0.
> 
> To make sure that devices are in D0 and that platform methods such as
> _REG are called, explicitly set all devices into D0 during initialization.
> 
> Fixes: 967577b062417 ("PCI/PM: Keep runtime PM enabled for unbound PCI devices")
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>

Applied to pci/pm for v6.16, thanks!

> ---
> v2:
>  * Move runtime PM calls after setting to D0
>  * Use pci_pm_power_up_and_verify_state()
> ---
>  drivers/pci/pci-driver.c |  6 ------
>  drivers/pci/pci.c        | 13 ++++++++++---
>  drivers/pci/pci.h        |  1 +
>  3 files changed, 11 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
> index c8bd71a739f72..082918ce03d8a 100644
> --- a/drivers/pci/pci-driver.c
> +++ b/drivers/pci/pci-driver.c
> @@ -555,12 +555,6 @@ static void pci_pm_default_resume(struct pci_dev *pci_dev)
>  	pci_enable_wake(pci_dev, PCI_D0, false);
>  }
>  
> -static void pci_pm_power_up_and_verify_state(struct pci_dev *pci_dev)
> -{
> -	pci_power_up(pci_dev);
> -	pci_update_current_state(pci_dev, PCI_D0);
> -}
> -
>  static void pci_pm_default_resume_early(struct pci_dev *pci_dev)
>  {
>  	pci_pm_power_up_and_verify_state(pci_dev);
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index e77d5b53c0cec..8d125998b30b7 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -3192,6 +3192,12 @@ void pci_d3cold_disable(struct pci_dev *dev)
>  }
>  EXPORT_SYMBOL_GPL(pci_d3cold_disable);
>  
> +void pci_pm_power_up_and_verify_state(struct pci_dev *pci_dev)
> +{
> +	pci_power_up(pci_dev);
> +	pci_update_current_state(pci_dev, PCI_D0);
> +}
> +
>  /**
>   * pci_pm_init - Initialize PM functions of given PCI device
>   * @dev: PCI device to handle.
> @@ -3202,9 +3208,6 @@ void pci_pm_init(struct pci_dev *dev)
>  	u16 status;
>  	u16 pmc;
>  
> -	pm_runtime_forbid(&dev->dev);
> -	pm_runtime_set_active(&dev->dev);
> -	pm_runtime_enable(&dev->dev);
>  	device_enable_async_suspend(&dev->dev);
>  	dev->wakeup_prepared = false;
>  
> @@ -3266,6 +3269,10 @@ void pci_pm_init(struct pci_dev *dev)
>  	pci_read_config_word(dev, PCI_STATUS, &status);
>  	if (status & PCI_STATUS_IMM_READY)
>  		dev->imm_ready = 1;
> +	pci_pm_power_up_and_verify_state(dev);
> +	pm_runtime_forbid(&dev->dev);
> +	pm_runtime_set_active(&dev->dev);
> +	pm_runtime_enable(&dev->dev);
>  }
>  
>  static unsigned long pci_ea_flags(struct pci_dev *dev, u8 prop)
> diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
> index b81e99cd4b62a..49165b739138b 100644
> --- a/drivers/pci/pci.h
> +++ b/drivers/pci/pci.h
> @@ -148,6 +148,7 @@ void pci_dev_adjust_pme(struct pci_dev *dev);
>  void pci_dev_complete_resume(struct pci_dev *pci_dev);
>  void pci_config_pm_runtime_get(struct pci_dev *dev);
>  void pci_config_pm_runtime_put(struct pci_dev *dev);
> +void pci_pm_power_up_and_verify_state(struct pci_dev *pci_dev);
>  void pci_pm_init(struct pci_dev *dev);
>  void pci_ea_init(struct pci_dev *dev);
>  void pci_msi_init(struct pci_dev *dev);
> -- 
> 2.43.0
>