Re: [igt-dev] [PATCH i-g-t 2/9] lib/igt_device: Get gfx PCI card root port

[Rodrigo Vivi <rodrigo.vivi@intel.com>]

On Mon, Apr 18, 2022 at 06:20:41PM +0530, Anshuman Gupta wrote:
> Utility library function to get the Gfx Card PCI topology
> root port pci device using libpaciaccess.
> root port will be used to get the real ACPI D state.
> 
> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
> Signed-off-by: Anshuman Gupta <anshuman.gupta@intel.com>
> ---
>  lib/igt_device.c | 28 ++++++++++++++++++++++++++++
>  lib/igt_device.h |  1 +
>  2 files changed, 29 insertions(+)
> 
> diff --git a/lib/igt_device.c b/lib/igt_device.c
> index 9794a9928..fddfba72c 100644
> --- a/lib/igt_device.c
> +++ b/lib/igt_device.c
> @@ -257,3 +257,31 @@ struct pci_device *igt_device_get_pci_device(int fd)
>  
>  	return pci_dev;
>  }
> +
> +/**
> + * igt_device_get_pci_root_port:
> + * @fd: the device.
> + *
> + * Looks up the graphics pci device root port using libpciaccess.
> + *
> + * Returns:
> + * The root port pci_device.
> + */
> +struct pci_device *
> +igt_device_get_pci_root_port(int fd)
> +{
> +	struct pci_device *pci_dev, *prev;
> +
> +	pci_dev = __igt_device_get_pci_device(fd, 0);
> +	igt_require(pci_dev);
> +
> +	while (pci_dev) {
> +		prev = pci_dev;
> +		pci_dev = pci_device_get_parent_bridge(pci_dev);
> +	}

Neat!

Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>



> +
> +	igt_debug("Root Port PCI device %04x:%02x:%02x.%01x\n",
> +		  prev->domain, prev->bus, prev->dev, prev->func);
> +
> +	return prev;
> +}
> diff --git a/lib/igt_device.h b/lib/igt_device.h
> index 1aaa840e2..800a0fcc3 100644
> --- a/lib/igt_device.h
> +++ b/lib/igt_device.h
> @@ -34,5 +34,6 @@ void igt_device_drop_master(int fd);
>  int igt_device_get_card_index(int fd);
>  struct pci_device *igt_device_get_pci_device(int fd);
>  struct pci_device *__igt_device_get_pci_device(int fd, unsigned int vf_id);
> +struct pci_device *igt_device_get_pci_root_port(int fd);
>  
>  #endif /* __IGT_DEVICE_H__ */
> -- 
> 2.26.2
>