Subject: Re: [PATCH net-next v9 2/5] PCI/ASPM: Add pcie_aspm_capable() helper

From: Sathyanarayanan Kuppuswamy <[email-masked]>
Date: Fri, 24 Feb 2023 22:10:53 -0800

On 2/24/23 7:46 PM, Kai-Heng Feng wrote:
> Introduce a new helper, pcie_aspm_capable(), to report ASPM capability.
> 
> The user will be introduced by next patch.

Instead of just saying next patch, just say which driver or use case is
going to use it.

> 
> Acked-by: Bjorn Helgaas <[email-masked]>
> Suggested-by: Bjorn Helgaas <[email-masked]>
> Signed-off-by: Kai-Heng Feng <[email-masked]>
> ---
> v9:
> v8:
>  - No change.
> 
> v7:
>  - Change subject.
> 
> v6:
>  - No change.
> 
> v5:
>  - No change.
> 
> v4:
>  - Report aspm_capable instead.
> 
> v3:
>  - This is a new patch
> 
>  drivers/pci/pcie/aspm.c | 11 +++++++++++
>  include/linux/pci.h     |  2 ++
>  2 files changed, 13 insertions(+)
> 
> diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
> index 692d6953f0970..d96bf0a362aa2 100644
> --- a/drivers/pci/pcie/aspm.c
> +++ b/drivers/pci/pcie/aspm.c
> @@ -1199,6 +1199,17 @@ bool pcie_aspm_enabled(struct pci_dev *pdev)
>  }
>  EXPORT_SYMBOL_GPL(pcie_aspm_enabled);
>  
> +bool pcie_aspm_capable(struct pci_dev *pdev)
> +{
> +	struct pcie_link_state *link = pcie_aspm_get_link(pdev);
> +
> +	if (!link)
> +		return false;
> +
> +	return link->aspm_capable;
> +}
> +EXPORT_SYMBOL_GPL(pcie_aspm_capable);
> +
>  static ssize_t aspm_attr_show_common(struct device *dev,
>  				     struct device_attribute *attr,
>  				     char *buf, u8 state)
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index adffd65e84b4e..fd56872883e14 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -1692,6 +1692,7 @@ int pci_disable_link_state_locked(struct pci_dev *pdev, int state);
>  void pcie_no_aspm(void);
>  bool pcie_aspm_support_enabled(void);
>  bool pcie_aspm_enabled(struct pci_dev *pdev);
> +bool pcie_aspm_capable(struct pci_dev *pdev);
>  #else
>  static inline int pci_disable_link_state(struct pci_dev *pdev, int state)
>  { return 0; }
> @@ -1700,6 +1701,7 @@ static inline int pci_disable_link_state_locked(struct pci_dev *pdev, int state)
>  static inline void pcie_no_aspm(void) { }
>  static inline bool pcie_aspm_support_enabled(void) { return false; }
>  static inline bool pcie_aspm_enabled(struct pci_dev *pdev) { return false; }
> +static inline bool pcie_aspm_capable(struct pci_dev *pdev) { return false; }
>  #endif
>  
>  #ifdef CONFIG_PCIEAER

-- 
Sathyanarayanan Kuppuswamy
Linux Kernel Developer