linux/drivers/pci/pcie/Kconfig
Bartlomiej Zolnierkiewicz fe73c23d7a PCI: pcie: Remove redundant 'default n' from Kconfig
'default n' is the default value for any bool or tristate Kconfig setting
so there is no need to write it explicitly.

Also since commit f467c5640c ("kconfig: only write '# CONFIG_FOO is not
set' for visible symbols") the Kconfig behavior is the same regardless of
'default n' being present or not:

    ...
    One side effect of (and the main motivation for) this change is making
    the following two definitions behave exactly the same:

        config FOO
                bool

        config FOO
                bool
                default n

    With this change, neither of these will generate a
    '# CONFIG_FOO is not set' line (assuming FOO isn't selected/implied).
    That might make it clearer to people that a bare 'default n' is
    redundant.
    ...

Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2018-10-18 14:05:29 -05:00

146 lines
3.9 KiB
Plaintext

# SPDX-License-Identifier: GPL-2.0
#
# PCI Express Port Bus Configuration
#
config PCIEPORTBUS
bool "PCI Express Port Bus support"
depends on PCI
help
This automatically enables PCI Express Port Bus support. Users can
choose Native Hot-Plug support, Advanced Error Reporting support,
Power Management Event support and Virtual Channel support to run
on PCI Express Ports (Root or Switch).
#
# Include service Kconfig here
#
config HOTPLUG_PCI_PCIE
bool "PCI Express Hotplug driver"
depends on HOTPLUG_PCI && PCIEPORTBUS
help
Say Y here if you have a motherboard that supports PCI Express Native
Hotplug
When in doubt, say N.
config PCIEAER
bool "PCI Express Advanced Error Reporting support"
depends on PCIEPORTBUS
select RAS
default y
help
This enables PCI Express Root Port Advanced Error Reporting
(AER) driver support. Error reporting messages sent to Root
Port will be handled by PCI Express AER driver.
config PCIEAER_INJECT
tristate "PCI Express error injection support"
depends on PCIEAER
help
This enables PCI Express Root Port Advanced Error Reporting
(AER) software error injector.
Debugging AER code is quite difficult because it is hard
to trigger various real hardware errors. Software-based
error injection can fake almost all kinds of errors with the
help of a user space helper tool aer-inject, which can be
gotten from:
http://www.kernel.org/pub/linux/utils/pci/aer-inject/
#
# PCI Express ECRC
#
config PCIE_ECRC
bool "PCI Express ECRC settings control"
depends on PCIEAER
help
Used to override firmware/bios settings for PCI Express ECRC
(transaction layer end-to-end CRC checking).
When in doubt, say N.
#
# PCI Express ASPM
#
config PCIEASPM
bool "PCI Express ASPM control" if EXPERT
depends on PCI && PCIEPORTBUS
default y
help
This enables OS control over PCI Express ASPM (Active State
Power Management) and Clock Power Management. ASPM supports
state L0/L0s/L1.
ASPM is initially set up by the firmware. With this option enabled,
Linux can modify this state in order to disable ASPM on known-bad
hardware or configurations and enable it when known-safe.
ASPM can be disabled or enabled at runtime via
/sys/module/pcie_aspm/parameters/policy
When in doubt, say Y.
config PCIEASPM_DEBUG
bool "Debug PCI Express ASPM"
depends on PCIEASPM
help
This enables PCI Express ASPM debug support. It will add per-device
interface to control ASPM.
choice
prompt "Default ASPM policy"
default PCIEASPM_DEFAULT
depends on PCIEASPM
config PCIEASPM_DEFAULT
bool "BIOS default"
depends on PCIEASPM
help
Use the BIOS defaults for PCI Express ASPM.
config PCIEASPM_POWERSAVE
bool "Powersave"
depends on PCIEASPM
help
Enable PCI Express ASPM L0s and L1 where possible, even if the
BIOS did not.
config PCIEASPM_POWER_SUPERSAVE
bool "Power Supersave"
depends on PCIEASPM
help
Same as PCIEASPM_POWERSAVE, except it also enables L1 substates where
possible. This would result in higher power savings while staying in L1
where the components support it.
config PCIEASPM_PERFORMANCE
bool "Performance"
depends on PCIEASPM
help
Disable PCI Express ASPM L0s and L1, even if the BIOS enabled them.
endchoice
config PCIE_PME
def_bool y
depends on PCIEPORTBUS && PM
config PCIE_DPC
bool "PCI Express Downstream Port Containment support"
depends on PCIEPORTBUS && PCIEAER
help
This enables PCI Express Downstream Port Containment (DPC)
driver support. DPC events from Root and Downstream ports
will be handled by the DPC driver. If your system doesn't
have this capability or you do not want to use this feature,
it is safe to answer N.
config PCIE_PTM
bool "PCI Express Precision Time Measurement support"
depends on PCIEPORTBUS
help
This enables PCI Express Precision Time Measurement (PTM)
support.
This is only useful if you have devices that support PTM, but it
is safe to enable even if you don't.