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Commit 27235b15 authored by Logan Gunthorpe's avatar Logan Gunthorpe Committed by Bjorn Helgaas
Browse files

PCI/P2PDMA: Update pci_p2pdma_distance_many() documentation 

The comment describing pci_p2pdma_distance_many() still referred to
the devices being behind the same root port. This no longer applies
so reword the documentation.

Link: https://lore.kernel.org/r/20190730163545.4915-15-logang@deltatee.com
Link: https://lore.kernel.org/r/20190812173048.9186-15-logang@deltatee.com


Signed-off-by: default avatarLogan Gunthorpe <logang@deltatee.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
parent 5daf40b0

drivers/pci/p2pdma.c

+7 −8
Original line number Diff line number Diff line
@@ -517,15 +517,14 @@ upstream_bridge_distance_warn(struct pci_dev *provider, struct pci_dev *client, 
 * @num_clients: number of clients in the array

 * @verbose: if true, print warnings for devices when we return -1

 *

 * Returns -1 if any of the clients are not compatible (behind the same

 * root port as the provider), otherwise returns a positive number where

 * a lower number is the preferable choice. (If there's one client

 * that's the same as the provider it will return 0, which is best choice).

 * Returns -1 if any of the clients are not compatible, otherwise returns a

 * positive number where a lower number is the preferable choice. (If there's

 * one client that's the same as the provider it will return 0, which is best

 * choice).

 *

 * For now, "compatible" means the provider and the clients are all behind

 * the same PCI root port. This cuts out cases that may work but is safest

 * for the user. Future work can expand this to white-list root complexes that

 * can safely forward between each ports.

 * "compatible" means the provider and the clients are either all behind

 * the same PCI root port or the host bridges connected to each of the devices

 * are listed in the 'pci_p2pdma_whitelist'.

 */

int pci_p2pdma_distance_many(struct pci_dev *provider, struct device **clients,

			     int num_clients, bool verbose)