Re: [PATCH v3 v3] PCI: dwc: Add pci id for LECARC pcie pmu

[Braden Zhang]

On Mon, Jul 13, 2026 at 07:14:25AM +0200, Manivannan Sadhasivam wrote:
> Date: Mon, 13 Jul 2026 07:14:25 +0200
> From: Manivannan Sadhasivam <mani@xxxxxxxxxx>
> To: Braden Zhang <braden_zhang@xxxxxxxxxxxxxxx>
> Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>, Jingoo Han <jingoohan1@xxxxxxxxx>,
>  linux-pci@xxxxxxxxxxxxxxx, linux-kernel@xxxxxxxxxxxxxxx, Brett Zhou
>  <brett_zhou@xxxxxxxxxxxxxxx>, Bjorn Helgaas <helgaas@xxxxxxxxxx>
> Subject: Re: [PATCH v3 v3] PCI: dwc: Add pci id for LECARC pcie pmu
> 
> On Mon, Jul 13, 2026 at 10:10:13AM +0800, Braden Zhang wrote:
> > From: Brett Zhou <brett_zhou@xxxxxxxxxxxxxxx>
> > 
> > This patch adds support for the PCIe PMU found
> > on LECARC SoCs, which utilize the DesignWare PCIe Controller IP
> > 
> 
> LECARC looks like a ACPI based platform. I'm wondering how you are able to make
> use of this patch without adding the ACPI ID support to enumerate the DWC
> driver.
> 
> - Mani
> 
> > Signed-off-by: Brett Zhou <brett_zhou@xxxxxxxxxxxxxxx>
> > Reviewed-by: Bjorn Helgaas <helgaas@xxxxxxxxxx>
> > Signed-off-by: Braden Zhang <braden_zhang@xxxxxxxxxxxxxxx>
> > ---
> > 
> > ---
> > base-commit: a635d6748234582ea287c5ffeae28b9b23f91c7e
> > change-id: 20260710-pcie-pmu-5ef78c56c3b6
> > 
> > Best regards,
> > --  
> > Braden Zhang <braden_zhang@xxxxxxxxxxxxxxx>
> > 
> 
> -- 
Hi Mani,

Thanks for the review.

LECARC platforms use the standard DesignWare PCIe Controller, and the
existing DWC driver already handles the enumeration and basic
functionality through the generic PCIe core. This patch only adds the
PCI vendor ID to the vendor-specific capability (VSEC) list, which
enables the standard DWC RAS/DES feature detection.

We don't require a separate PMU driver or additional ACPI ID support
because the PMU functionality is already covered by the generic DWC
PMU framework. The existing driver infrastructure handles the PMU
features transparently once the vendor ID is recognized in the VSEC
table.

Please let us know if you have any other concerns.

Best regards,
Braden Zhang