Re: [RFC PATCH 1/5] pci/p2p: add a function to test peer to peer capability

From: Logan Gunthorpe
Date: Tue Jan 29 2019 - 13:24:41 EST




On 2019-01-29 10:47 a.m., jglisse@xxxxxxxxxx wrote:
> +bool pci_test_p2p(struct device *devA, struct device *devB)
> +{
> + struct pci_dev *pciA, *pciB;
> + bool ret;
> + int tmp;
> +
> + /*
> + * For now we only support PCIE peer to peer but other inter-connect
> + * can be added.
> + */
> + pciA = find_parent_pci_dev(devA);
> + pciB = find_parent_pci_dev(devB);
> + if (pciA == NULL || pciB == NULL) {
> + ret = false;
> + goto out;
> + }
> +
> + tmp = upstream_bridge_distance(pciA, pciB, NULL);
> + ret = tmp < 0 ? false : true;
> +
> +out:
> + pci_dev_put(pciB);
> + pci_dev_put(pciA);
> + return false;
> +}
> +EXPORT_SYMBOL_GPL(pci_test_p2p);

This function only ever returns false....

Logan