Re: [PATCH v3] PCI: dwc: Add suspend_poweroff flag for platforms with RC power loss

[sashiko-bot@kernel.org]

> From: Richard Zhu <hongxing.zhu@nxp.com>
> 
> Some platforms like i.MX power off their PCIe RC controllers during
> system suspend, requiring full re-initialization on resume. These
> platforms need to enter L2 state to properly notify endpoints before
> power loss.
> 
> According to PCIe base spec r7.0, sec 5.2, the system software should
> transition the device into D3Hot before broadcasting the PME_Turn_Off
> message to initiate L2 entry. In practice, endpoint drivers properly
> put their devices into D3hot during the suspend flow. However, some
> wakeup-capable endpoint devices that don't support PME from D3cold
> fail the D3cold capability check in pci_host_common_d3cold_possible(),
> which currently prevents L2 entry even though the devices are already
> in the required D3hot state.
> 
> For platforms where the RC loses power during suspend, L2 entry is
> essential regardless of D3cold support, as the link will be lost anyway
> when the RC powers off. Without L2 entry, endpoints are not properly
> notified before power loss, which can cause issues during resume and
> reinitialization.
> 
> Add a suspend_poweroff flag to allow L2 entry for devices that are in
> D3hot but fail the D3cold capability check, and enable it for i.MX PCIe
> controllers that lose power during suspend.
> 
> Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>

Sashiko has reviewed this patch and found no issues. It looks great!

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Sashiko AI review · https://sashiko.dev/#/patchset/20260917063322.4102035-1-hongxing.zhu@oss.nxp.com?part=1