linux/drivers/pps/Kconfig
Maciej S. Szmigiero ab47deb6bb pps: kc: fix non-tickless system config dependency
CONFIG_NO_HZ currently only sets the default value of dynticks config so
if PPS kernel consumer needs periodic timer ticks it should depend on
!CONFIG_NO_HZ_COMMON instead of !CONFIG_NO_HZ.

Otherwise it is possible to enable it even on tickless system which has
CONFIG_NO_HZ not set and CONFIG_NO_HZ_IDLE (or CONFIG_NO_HZ_FULL) set.

Link: http://lkml.kernel.org/r/57E2B769.50202@maciej.szmigiero.name
Signed-off-by: Maciej S. Szmigiero <mail@maciej.szmigiero.name>
Acked-by: Rodolfo Giometti <giometti@enneenne.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11 15:06:32 -07:00

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#
# PPS support configuration
#
menu "PPS support"
config PPS
tristate "PPS support"
---help---
PPS (Pulse Per Second) is a special pulse provided by some GPS
antennae. Userland can use it to get a high-precision time
reference.
Some antennae's PPS signals are connected with the CD (Carrier
Detect) pin of the serial line they use to communicate with the
host. In this case use the SERIAL_LINE client support.
Some antennae's PPS signals are connected with some special host
inputs so you have to enable the corresponding client support.
To compile this driver as a module, choose M here: the module
will be called pps_core.ko.
if PPS
config PPS_DEBUG
bool "PPS debugging messages"
help
Say Y here if you want the PPS support to produce a bunch of debug
messages to the system log. Select this if you are having a
problem with PPS support and want to see more of what is going on.
config NTP_PPS
bool "PPS kernel consumer support"
depends on !NO_HZ_COMMON
help
This option adds support for direct in-kernel time
synchronization using an external PPS signal.
It doesn't work on tickless systems at the moment.
endif
source drivers/pps/clients/Kconfig
source drivers/pps/generators/Kconfig
endmenu