Re: [PATCH v2] 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. However, some endpoint devices fail the
> D3cold capability check in pci_host_common_d3cold_possible(), which
> would normally prevent L2 entry.
> 
> For platforms where the RC loses power during suspend, L2 entry is
> essential regardless of D3cold support, as the link will be lost anyway.
> Add a suspend_poweroff flag to force L2 entry in such cases, and enable
> it for i.MX PCIe controllers.
> 
> Note: This violates the spec requirement that devices be in D3Hot before
> PME_Turn_Off, but is necessary for proper operation on platforms with RC
> power loss 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/20260717074121.3214222-1-hongxing.zhu@oss.nxp.com?part=1