Module Name: src Committed By: snj Date: Mon Feb 12 18:42:20 UTC 2018
Modified Files: src/sys/arch/sparc/sparc [netbsd-7]: timer.c timer_sun4m.c timerreg.h Log Message: Pull up following revision(s) (requested by mrg in ticket #1552): sys/arch/sparc/sparc/timer.c: 1.33-1.34 sys/arch/sparc/sparc/timer_sun4m.c: 1.31 sys/arch/sparc/sparc/timerreg.h: 1.10 fix time goes backwards problems on sparc. there are a few things here: - there's a race between reading the limit register (which clears the interrupt and the limit bit) and increasing the latest offset. this can happen easily if an interrupt comes between the read and the call to tickle_tc() that increases the offset (i obverved this actually happening.) - in early boot, sometimes the counter can cycle twice before the tickle happens. to handle these issues, add two workarounds: - if the limit bit isn't set, but the counter value is less than the previous value, and the offset hasn't changed, use the same fixup as if the limit bit was set. this handles the first case above. - add a hard-workaround for never allowing returning a smaller value (except during 32 bit overflow): if the result is less than the last result, add fixups until it does (or until it would overflow.) the first workaround fixes general run-time issues, and the second fixes issues only seen during boot. also expand some comments in timer_sun4m.c and re-enable the sun4m sub-microsecond tmr_ustolim4m() support (but it's always called with at least 'tick' microseconds, so the end result is the same.) -- fix hang at 4B microseconds (1h12 or so), and simplify part of the previous To generate a diff of this commit: cvs rdiff -u -r1.32 -r22.214.171.124 src/sys/arch/sparc/sparc/timer.c cvs rdiff -u -r1.30 -r126.96.36.199 src/sys/arch/sparc/sparc/timer_sun4m.c cvs rdiff -u -r1.9 -r188.8.131.52 src/sys/arch/sparc/sparc/timerreg.h Please note that diffs are not public domain; they are subject to the copyright notices on the relevant files.