Date: Fri, 04 Jul 2008 09:20:55 -0700 From: Nate Lawson <nate@root.org> To: Bruce Evans <brde@optusnet.com.au> Cc: Joerg Wunsch <joerg_wunsch@uriah.heep.sax.de>, freebsd-acpi@freebsd.org Subject: Re: HP/Compaq nx6325 clock "jumping around" Message-ID: <486E4DE7.60807@root.org> In-Reply-To: <20080703145049.S6189@delplex.bde.org> References: <20080702191827.GK1469@uriah.heep.sax.de> <20080703145049.S6189@delplex.bde.org>
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Bruce Evans wrote: > On Wed, 2 Jul 2008, Joerg Wunsch wrote: > >> On a nx6325 running 6-stable (because I couldn't get 7.x to work with >> ACPI at all so far), the main clock is frequently "jumping", up to a >> level where ntpd eventually gives up: > > I know of the following bugs in time on nx6325: > - pressing the lid switch to turn the screen off makes the time jump by > almost precisely 1 second using any timecounter. The system appears > to spend the 1 second in something like SMM mode with all interrupts > and all timecounters stopped. More precisely, the jump is: > ACPI-fast and TSC: -1.000000 +- 10 uS > i8254: -1.043000 +- 1 mS I'm not sure how to do anything about this. Sounds like a BIOS bug. > - dynamic recalibration of cpu_tick_frequency has never worked. This > is a MI bug, and only affects process times. cpu_tick_frequency is > never adjusted downwards (except for a full recalibration). Thus > any glitches in the cpu_tick clock (TSC on nx6325), e.g., from the > SMM bug or entering ddb) cause cpu_tick_frequency to creep or jump > upwards and never come down. This reminds me -- the algorithm for estimating the cpu frequency needs improvement. You had a patch you sent me that reduced its error by a lot. Would you commit it? > dev.cpu.0.freq: 1985 > dev.cpu.0.freq_levels: 1985/-1 1736/-1 1488/-1 1240/-1 992/-1 744/-1 > 496/-1 248/-1 > > Once I used some performance/power-reduction config and got a list like > yours. > > 1985 actually gives 1995 MHz. Your freq estimation patch does better than this. -- Nate
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