[PATCH 1/1][SRU][N] PCI: Explicitly put devices into D0 when initializing

[Stefan Bader]

On 22.07.25 11:58, Thomas Lamprecht wrote:
> Am 29.05.25 um 03:15 schrieb AceLan Kao:
>> From: Mario Limonciello <mario.limonciello at amd.com>
>>
>> BugLink: https://bugs.launchpad.net/bugs/2110090
>>
>> AMD BIOS team has root caused an issue that NVMe storage failed to come
>> back from suspend to a lack of a call to _REG when NVMe device was probed.
>>
>> 112a7f9c8edbf ("PCI/ACPI: Call _REG when transitioning D-states") added
>> support for calling _REG when transitioning D-states, but this only works
>> if the device actually "transitions" D-states.
>>
>> 967577b062417 ("PCI/PM: Keep runtime PM enabled for unbound PCI devices")
>> added support for runtime PM on PCI devices, but never actually
>> 'explicitly' sets the device to D0.
>>
>> To make sure that devices are in D0 and that platform methods such as
>> _REG are called, explicitly set all devices into D0 during initialization.
>>
>> Fixes: 967577b062417 ("PCI/PM: Keep runtime PM enabled for unbound PCI devices")
>> Signed-off-by: Mario Limonciello <mario.limonciello at amd.com>
>> Signed-off-by: Bjorn Helgaas <bhelgaas at google.com>
>> Tested-by: Denis Benato <benato.denis96 at gmail.com>
>> Tested-By: Yijun Shen <Yijun_Shen at Dell.com>
>> Tested-By: David Perry <david.perry at amd.com>
>> Reviewed-by: Rafael J. Wysocki <rafael at kernel.org>
>> Link: https://patch.msgid.link/20250424043232.1848107-1-superm1@kernel.org
>> (cherry picked from commit 4d4c10f763d7808fbade28d83d237411603bca05)
>> Signed-off-by: Chia-Lin Kao (AceLan) <acelan.kao at canonical.com>
> 
> FYI: This causes regressions on PCI passthrough to QEMU/KVM, among other
> things. A colleague found that the following patch on top fixes it here:
> 
> https://lore.kernel.org/all/20250611233117.61810-1-superm1@kernel.org/
> 
> Same holds for the Plucky backport in patch mail id:
> <20250529010730.1863186-2-acelan.kao at canonical.com>
> 
> 

Hello Thomas,

thank you for the notification. I prepared 
https://bugs.launchpad.net/ubuntu/plucky/+source/linux/+bug/2117494 and 
submitted the fix to our mailing list.

-- 
- Stefan
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