Re: [PATCH] PCI/DPC: Honor "pcie_ports=native" when enabling DPC

[Guixin Liu <kanie@linux.alibaba.com>]

在 2026/9/4 10:34, Guixin Liu 写道:
>
>
> 在 2026/9/4 07:05, Bjorn Helgaas 写道:
>> On Tue, Sep 01, 2026 at 02:45:54PM +0800, Guixin Liu wrote:
>>> Commit 97ca178c899d ("PCI/DPC: Allow DPC on all Downstream Ports when
>>> OS controls AER") replaced the AER service bit with host->native_aer
>>> when deciding whether to create a DPC service device. Unlike the AER
>>> service bit, host->native_aer does not reflect the "pcie_ports=native"
>>> command-line override.
>>>
>>> Consequently, if firmware retains AER control, "pcie_ports=native" no
>>> longer enables DPC on Root Ports that advertise both AER and DPC, even
>>> though the option is documented to force native DPC handling.
>>>
>>> Check pcie_ports_native explicitly so both command-line overrides
>>> continue to work.
>>>
>>> Fixes: 97ca178c899d ("PCI/DPC: Allow DPC on all Downstream Ports 
>>> when OS controls AER")
>>> Cc: stable@vger.kernel.org
>>> Signed-off-by: Guixin Liu <kanie@linux.alibaba.com>
>>> ---
>>>   drivers/pci/pcie/portdrv.c | 2 +-
>>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/pci/pcie/portdrv.c b/drivers/pci/pcie/portdrv.c
>>> index a9cbfc1d2bc7..a05ee7980fb2 100644
>>> --- a/drivers/pci/pcie/portdrv.c
>>> +++ b/drivers/pci/pcie/portdrv.c
>>> @@ -264,7 +264,7 @@ static int get_port_device_capability(struct 
>>> pci_dev *dev)
>>>        */
>>>       if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DPC) &&
>>>           pci_aer_available() &&
>>> -        (pcie_ports_dpc_native || host->native_aer))
>>> +        (pcie_ports_native || pcie_ports_dpc_native || 
>>> host->native_aer))
>> Oh my goodness.  I think I completely dropped ball on this YEARS ago.
>>
>> It's crazy that we have "pcie_ports_native" checking littered all
>> over.  I think we should instead treat host->native_* as the single
>> source of truth, and pay attention to pcie_ports_native when setting
>> host->native_*.
>>
>> Sathy did some great work to do exactly that in 2020, and I never got
>> it merged.  I wish I had some great excuse, but I looked at my 2020
>> calendar and couldn't find one.  I think I just blew it.
>>
>> So I think we should resurrect that series and update it as needed and
>> solve the problem that way.  I dug out the links just for
>> completeness, but we should probably just start with the most recent
>> ones (v11 or v12):
>>
>>    # v2 
>> https://lore.kernel.org/r/cover.1590355211.git.sathyanarayanan.kuppuswamy@linux.intel.com/
>>    # v3 
>> https://lore.kernel.org/r/cover.1590355824.git.sathyanarayanan.kuppuswamy@linux.intel.com/
>>    # v4 
>> https://lore.kernel.org/r/cover.1590534843.git.sathyanarayanan.kuppuswamy@linux.intel.com/
>>    # v5 
>> https://lore.kernel.org/r/cover.1591545462.git.sathyanarayanan.kuppuswamy@linux.intel.com/
>>    # v6 
>> https://lore.kernel.org/r/cover.1593195899.git.sathyanarayanan.kuppuswamy@linux.intel.com/
>>    # v7 
>> https://lore.kernel.org/r/cover.1595006564.git.sathyanarayanan.kuppuswamy@linux.intel.com/
>>    # v8 
>> https://lore.kernel.org/r/cover.1595649348.git.sathyanarayanan.kuppuswamy@linux.intel.com/
>>    # v9 
>> https://lore.kernel.org/r/cover.1600457297.git.sathyanarayanan.kuppuswamy@linux.intel.com/
>>    # v9 
>> https://lore.kernel.org/r/20200928011131.MI-pJpJNRQw6c35j_O6019flLWHe08C4WvKPmKEbnik@z/
>>    # v10 
>> https://lore.kernel.org/r/cover.1603738449.git.sathyanarayanan.kuppuswamy@linux.intel.com/
>>    # v11 
>> https://lore.kernel.org/r/cover.1603766889.git.sathyanarayanan.kuppuswamy@linux.intel.com/
>>    # v12 
>> https://lore.kernel.org/r/20201126011816.711106-1-helgaas@kernel.org/
Hi Bjorn, still not see you resurrect this series.

Best Regards,
Guixin Liu
> Yeah, this series is better than mine, wait for your to recover them.
>
> In addition, we should add "Fixes: 97ca178c899d ("PCI/DPC: Allow DPC 
> on all Downstream Ports when OS controls AER")" also.
>
> Best Regards,
> Guixin Liu
>>> services |= PCIE_PORT_SERVICE_DPC;
>>>         /* Enable bandwidth control if more than one speed is 
>>> supported. */
>>> -- 
>>> 2.43.7
>>>