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

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

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/
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
>>