PCI: Add function to obtain minimum link width and speed
authorJacob Keller <jacob.e.keller@intel.com>
Wed, 31 Jul 2013 06:53:26 +0000 (06:53 +0000)
committerJeff Kirsher <jeffrey.t.kirsher@intel.com>
Wed, 31 Jul 2013 07:30:20 +0000 (00:30 -0700)
commit81377c8d3563e7aec5c8baaaacacb48034f430a0
treefe58387e3bea2c5b5656e2a81d9bfd558b2a3d83
parent59da381ee2afc806f85becf3aa64ffc952355552
PCI: Add function to obtain minimum link width and speed

A PCI Express device can potentially report a link width and speed which it will
not properly fulfill due to being plugged into a slower link higher in the
chain. This function walks up the PCI bus chain and calculates the minimum link
width and speed of this entire chain. This can be useful to enable a device to
determine if it has enough bandwidth for optimum functionality.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
drivers/pci/pci.c
include/linux/pci.h