Hans Petter Selasky 0eb8d46232 Improve USB polling mode by not locking any mutexes, asserting any ... mutexes or using any callouts when active. Trying to lock a mutex when KDB is active or the scheduler is stopped can result in infinite wait loops. The same goes for calling callout related functions which in turn lock mutexes. If the USB controller at which a USB keyboard is connected is idle when KDB is entered, polling the USB keyboard via USB will always succeed. Else polling may fail depending on which state the USB subsystem and USB interrupt handler is in. This is unavoidable unless KDB can wait for USB interrupt threads to complete before stalling the CPU(s). Tested by: Bruce Evans <bde@freebsd.org> MFC after: 4 weeks		2016-09-14 12:07:34 +00:00
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usb_quirk.c	Improve USB polling mode by not locking any mutexes, asserting any	2016-09-14 12:07:34 +00:00
usb_quirk.h