Re: [PATCH v2 2/2] PCI: Remove redundant MPS configuration

[Hans Zhang]

On 2025/4/26 02:13, Pali Rohár wrote:
> On Friday 25 April 2025 17:57:08 Hans Zhang wrote:
> > diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c
> > index a29796cce420..d8852892994a 100644
> > --- a/drivers/pci/controller/pci-aardvark.c
> > +++ b/drivers/pci/controller/pci-aardvark.c
> > @@ -549,9 +549,7 @@ static void advk_pcie_setup_hw(struct advk_pcie *pcie)
> >   	reg = advk_readl(pcie, PCIE_CORE_PCIEXP_CAP + PCI_EXP_DEVCTL);
> >   	reg &= ~PCI_EXP_DEVCTL_RELAX_EN;
> >   	reg &= ~PCI_EXP_DEVCTL_NOSNOOP_EN;
> > -	reg &= ~PCI_EXP_DEVCTL_PAYLOAD;
> >   	reg &= ~PCI_EXP_DEVCTL_READRQ;
> > -	reg |= PCI_EXP_DEVCTL_PAYLOAD_512B;
> >   	reg |= PCI_EXP_DEVCTL_READRQ_512B;
> >   	advk_writel(pcie, reg, PCIE_CORE_PCIEXP_CAP + PCI_EXP_DEVCTL);
> >   
> > --
> > 2.25.1
>
> Please do not remove this code. It is required part of the
> initialization of the aardvark PCI controller at the specific phase,
> as defined in the Armada 3700 Functional Specification.

Hi Pali,

This series of patches is discussing the initialization of DevCtl.MPS by 
the Root Port. Please look at the first patch I submitted. If there is a 
reasonable method in the end, DevCtl.MPS will also be configured 
successfully. The PCIe maintainer will give the review opinions. Please 
rest assured that it will not affect the functions of the aardvark PCI 
controller.

Rockchip's RK3588 also has the same problem.


https://patchwork.kernel.org/project/linux-pci/patch/20250416151926.140202-1-18255117159@xxxxxxx/

Best regards,
Hans