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78236571a5
Limit the number of "expensive" rfkill workqueue operations per second, in order to not hog system resources too much when faced with a rogue source of rfkill input events. The old rfkill-input code (before it was refactored) had such a limit in place. It used to drop new events that were past the rate limit. This behaviour was not implemented as an anti-DoS measure, but rather as an attempt to work around deficiencies in input device drivers which would issue multiple KEY_FOO events too soon for a given key FOO (i.e. ones that do not implement mechanical debouncing properly). However, we can't really expect such issues to be worked around by every input handler out there, and also by every userspace client of input devices. It is the input device driver's responsability to do debouncing instead of spamming the input layer with bogus events. The new limiter code is focused only on anti-DoS behaviour, and tries to not lose events (instead, it coalesces them when possible). The transmitters are updated once every 200ms, maximum. Care is taken not to delay a request to _enter_ rfkill transmitter Emergency Power Off (EPO) mode. If mistriggered (e.g. by a jiffies counter wrap), the code delays processing *once* by 200ms. Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br> Cc: Ivo van Doorn <IvDoorn@gmail.com> Cc: Dmitry Torokhov <dtor@mail.ru> Signed-off-by: John W. Linville <linville@tuxdriver.com> |
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| .. | ||
| Kconfig | ||
| Makefile | ||
| rfkill-input.c | ||
| rfkill-input.h | ||
| rfkill.c | ||