Re: [PATCH 1/2] PCI/PM: Disable bridge D3 on Lenovo ThinkCentre M90n-1

[sashiko-bot@kernel.org]

> On the Lenovo ThinkCentre M90n-1 (board 314D), suspending the empty
> Root Port 9 turns off a clock needed by the onboard RTL8168 behind
> Root Port 12.  The NIC becomes inaccessible and r8169 fails to probe
> with "Unable to change power state from D3cold to D0".
> 
> The RP09.PXP_._OFF method gates PCH SRC clock 1, which also supplies
> the NIC behind Root Port 12.  Keeping Root Port 9 in D0 preserves
> that clock and allows the NIC to probe.  Commit 4d4c10f763d7 ("PCI:
> Explicitly put devices into D0 when initializing") exposed the firmware
> bug on every boot by ensuring that the first runtime suspend executes
> the power resource's _OFF method.
> 
> Add the board to bridge_d3_blacklist to prevent bridge D3 transitions.
> Check the blacklist before platform_pci_bridge_d3(), since ACPI allows
> D3 on the affected hotplug port and would otherwise bypass the quirk.
> 
> Fixes: 4d4c10f763d7 ("PCI: Explicitly put devices into D0 when initializing")
> Reported-by: Joshua Perry <josh@6bit.com>
> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=222179
> Cc: stable@vger.kernel.org
> Signed-off-by: Mario Limonciello <superm1@kernel.org>

Sashiko has reviewed this patch and found no issues.

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