[PATCH v7 0/2] PCI: Configure Root Port MPS during host probing

[Hans Zhang]

On 7/14/26 19:06, Hans Zhang wrote:
> 
> 
> On 6/23/26 01:14, Bjorn Helgaas wrote:
>> On Fri, Jun 19, 2026 at 11:29:39PM +0800, Hans Zhang wrote:
>>> On 5/6/26 22:00, Manivannan Sadhasivam wrote:
>>>> On Fri, Nov 28, 2025 at 01:09:06AM +0800, Hans Zhang wrote:
>>>>> Current PCIe initialization exhibits a key optimization gap: Root 
>>>>> Ports
>>>>> may operate with non-optimal Maximum Payload Size (MPS) settings. 
>>>>> While
>>>>> downstream device configuration is handled during bus enumeration, 
>>>>> Root
>>>>> Port MPS values inherited from firmware or hardware defaults often 
>>>>> fail
>>>>> to utilize the full capabilities supported by controller hardware. 
>>>>> This
>>>>> results in suboptimal data transfer efficiency throughout the PCIe
>>>>> hierarchy.
>>>>>
>>>>> This patch series addresses this by:
>>>>>
>>>>> 1. Core PCI enhancement (Patch 1):
>>>>> - Proactively configures Root Port MPS during host controller probing
>>>>> - Sets initial MPS to hardware maximum (128 << dev->pcie_mpss)
>>>>> - Conditional on PCIe bus tuning being enabled (PCIE_BUS_TUNE_OFF 
>>>>> unset)
>>>>>     and not in PCIE_BUS_PEER2PEER mode (which requires default 128 
>>>>> bytes)
>>>>> - Maintains backward compatibility via PCIE_BUS_TUNE_OFF check
>>>>> - Preserves standard MPS negotiation during downstream enumeration
>>>>>
>>>>> 2. Driver cleanup (Patch 2):
>>>>> - Removes redundant MPS configuration from Meson PCIe controller 
>>>>> driver
>>>>> - Functionality is now centralized in PCI core
>>>>> - Simplifies driver maintenance long-term
>>>>>
>>>>
>>>> For the series,
>>>>
>>>> Reviewed-by: Manivannan Sadhasivam <mani at kernel.org>
>>>>
>>>> Bjorn: Could you please take a look? This series has been floating 
>>>> for a
>>>> while...
>>>
>>> Hello Bjorn,
>>>
>>> Any chance for this series to be applied?
>>
>> It's too late for v7.2; we're already more than halfway through the
>> merge window.  We can look again for v7.3 after v7.2-rc1.
> 
> Hello Bjorn,
> 
> Gentle ping on this series.
> 

Hello Bjorn,

Would you have time to take a look at this series? If there is anything 
else I can do to improve, I will do it.


Best regards,
Hans