linux/drivers/pci
Keith Busch 2078e1e7f7 PCI/LINK: Add Kconfig option (default off)
e8303bb7a7 ("PCI/LINK: Report degraded links via link bandwidth
notification") added dmesg logging whenever a link changes speed or width
to a state that is considered degraded.  Unfortunately, it cannot
differentiate signal integrity-related link changes from those
intentionally initiated by an endpoint driver, including drivers that may
live in userspace or VMs when making use of vfio-pci.  Some GPU drivers
actively manage the link state to save power, which generates a stream of
messages like this:

  vfio-pci 0000:07:00.0: 32.000 Gb/s available PCIe bandwidth, limited by 2.5 GT/s x16 link at 0000:00:02.0 (capable of 64.000 Gb/s with 5 GT/s x16 link)

Since we can't distinguish the intentional changes from the signal
integrity issues, leave the reporting turned off by default.  Add a Kconfig
option to turn it on if desired.

Fixes: e8303bb7a7 ("PCI/LINK: Report degraded links via link bandwidth notification")
Link: https://lore.kernel.org/linux-pci/20190501142942.26972-1-keith.busch@intel.com
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2019-05-02 08:34:32 -05:00
..
controller pci-v5.1-changes 2019-03-09 14:57:08 -08:00
endpoint PCI: pci-epf-test: Use pci_epc_get_features() to get EPC features 2019-02-15 10:01:16 +00:00
hotplug PCI: pciehp: Ignore Link State Changes after powering off a slot 2019-04-10 16:06:43 -05:00
pcie PCI/LINK: Add Kconfig option (default off) 2019-05-02 08:34:32 -05:00
switch cross-tree: phase out dma_zalloc_coherent() 2019-01-08 07:58:37 -05:00
access.c PCI: Uninline PCI bus accessors for better ftracing 2018-10-04 16:37:37 -05:00
ats.c PCI/ATS: Add pci_ats_page_aligned() interface 2019-02-26 11:08:07 +01:00
bus.c PCI: Fix is_added/is_busmaster race condition 2018-07-31 11:27:54 -05:00
ecam.c PCI: Add SPDX GPL-2.0 to replace GPL v2 boilerplate 2018-01-28 15:48:29 -06:00
host-bridge.c PCI: Tidy comments 2018-03-19 14:20:43 -05:00
iov.c PCI/IOV: Add flag so platforms can skip VF scanning 2019-01-01 19:04:37 -06:00
irq.c PCI: Use IRQF_ONESHOT if pci_request_irq() called with no handler 2018-07-31 10:43:43 -05:00
Kconfig PCI: Fix PCI kconfig menu organization 2019-01-14 17:01:20 -06:00
Makefile PCI/ACPI: Allow ACPI to be built without CONFIG_PCI set 2018-12-20 10:19:49 +01:00
mmap.c PCI: Tidy comments 2018-03-19 14:20:43 -05:00
msi.c PCI/MSI: Remove obsolete sanity checks for multiple interrupt sets 2019-02-18 11:21:29 +01:00
of.c PCI: Use of_node_name_eq() for node name comparisons 2019-01-22 14:13:02 -06:00
p2pdma.c pci-v4.21-changes 2019-01-05 17:57:34 -08:00
pci-acpi.c PCI / ACPI: Identify untrusted PCI devices 2018-12-05 12:01:55 +03:00
pci-bridge-emul.c PCI: pci-bridge-emul: Extend pci_bridge_emul_init() with flags 2019-02-22 10:51:14 +00:00
pci-bridge-emul.h PCI: pci-bridge-emul: Extend pci_bridge_emul_init() with flags 2019-02-22 10:51:14 +00:00
pci-driver.c PCI: Clean up usage of __u32 type 2019-02-08 13:40:36 -06:00
pci-label.c PCI: Tidy comments 2018-03-19 14:20:43 -05:00
pci-mid.c x86/cpu: Sanitize FAM6_ATOM naming 2018-10-02 10:14:32 +02:00
pci-pf-stub.c PCI/IOV: Add pci-pf-stub driver for PFs that only enable VFs 2018-04-24 16:47:16 -05:00
pci-stub.c PCI: Tidy comments 2018-03-19 14:20:43 -05:00
pci-sysfs.c PCI: pci-sysfs.c: convert to use BUS_ATTR_WO 2019-01-22 14:25:26 +01:00
pci.c PCI: Fix issue with "pci=disable_acs_redir" parameter being ignored 2019-04-12 15:32:08 -05:00
pci.h PCI/LINK: Deduplicate bandwidth reports for multi-function devices 2019-03-25 17:59:07 -05:00
probe.c PCI/LINK: Deduplicate bandwidth reports for multi-function devices 2019-03-25 17:59:07 -05:00
proc.c Remove 'type' argument from access_ok() function 2019-01-03 18:57:57 -08:00
quirks.c PCI: Add function 1 DMA alias quirk for Marvell 9170 SATA controller 2019-04-05 16:11:16 -05:00
remove.c PCI/ASPM: Fix link_state teardown on device removal 2018-09-17 16:32:23 -05:00
rom.c PCI: Make pci_get_rom_size() static 2018-06-29 21:17:26 -05:00
search.c PCI: Tidy comments 2018-03-19 14:20:43 -05:00
setup-bus.c PCI: Rely on config space header type, not class code 2019-01-30 10:57:08 -06:00
setup-irq.c PCI: Tidy comments 2018-03-19 14:20:43 -05:00
setup-res.c PCI: Remove messages about reassigning resources 2018-04-11 08:46:50 -05:00
slot.c PCI/ERR: Use slot reset if available 2018-09-21 12:18:10 -05:00
syscall.c PCI: Tidy comments 2018-03-19 14:20:43 -05:00
vc.c Merge branch 'pci/spdx' into next 2018-02-01 11:40:07 -06:00
vpd.c PCI/VPD: Check for VPD access completion before checking for timeout 2018-08-14 16:04:46 -05:00
xen-pcifront.c PCI: Tidy comments 2018-03-19 14:20:43 -05:00