Re: [PATCH] perf/dwc_pcie: Qualify RAS DES VSEC Capability by Vendor, Revision

[Bjorn Helgaas <helgaas@kernel.org>]

On Tue, Dec 10, 2024 at 08:04:17PM +0800, Shuai Xue wrote:
> 在 2024/12/10 06:29, Bjorn Helgaas 写道:
> > From: Bjorn Helgaas <bhelgaas@google.com>
> > 
> > PCI Vendor-Specific (VSEC) Capabilities are defined by each vendor.
> > Devices from different vendors may advertise a VSEC Capability with the DWC
> > RAS DES functionality, but the vendors may assign different VSEC IDs.
> > 
> > Search for the DWC RAS DES Capability using the VSEC ID and VSEC Rev
> > chosen by the vendor.

> > -	for (vid = dwc_pcie_vendor_ids; vid->vendor_id; vid++) {
> > +	for (vid = dwc_pcie_pmu_vsec_ids; vid->vendor_id; vid++) {
> 
> How about checking the pdev->vendor with vid->vendor_id before
> search the vesc cap?
> 
> +		if (pdev->vendor != vid->vendor_id)
> +			continue;

Every user of VSEC needs to specify the (Vendor ID, VSEC ID) and
verify that the Vendor ID matches the device Vendor ID, so
pci_find_vsec_capability() does this check internally, so I don't
think we need to do it here.

> >   		vsec = pci_find_vsec_capability(pdev, vid->vendor_id,
> > -						DWC_PCIE_VSEC_RAS_DES_ID);
> > -		if (vsec)
> > -			break;
> > +						vid->vsec_id);