Re: [PATCH v3] PCI: Add D3 support for PCI bridges in DT based platforms

Lukas Wunner
2024-02-14T12:19:54Z

On Wed, Feb 14, 2024 at 05:16:09PM +0530, Manivannan Sadhasivam wrote:
> Currently, PCI core will enable D3 support for PCI bridges only when the
> following conditions are met:
>
> 1. Platform is ACPI based
> 2. Thunderbolt controller is used
> 3. pcie_port_pm=force passed in cmdline
>
> While options 1 and 2 do not apply to most of the DT based platforms,
> option 3 will make the life harder for distro maintainers. Due to this,
> runtime PM is also not getting enabled for the bridges.
>
> To fix this, let's make use of the "supports-d3" property [1] in the bridge
> DT nodes to enable D3 support for the capable bridges. This will also allow
> the capable bridges to support runtime PM, thereby conserving power.
[...]
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

Reviewed-by: Lukas Wunner <lukas@wunner.de>