Date: Mon, 25 Mar 2019 18:05:35 +0100 From: Bernd Walter <ticso@cicely7.cicely.de> To: Ian Lepore <ian@freebsd.org> Cc: ticso@cicely.de, Karl Denninger <karl@denninger.net>, "freebsd-arm@freebsd.org" <freebsd-arm@freebsd.org> Subject: Re: Options for FBSD support with LCD device - new project [[Maybe related: I2c issues on the Pi2]] Message-ID: <20190325170534.GM57400@cicely7.cicely.de> In-Reply-To: <fc694564b1cf8bfa781ff86a7d5d7d09de68ad0e.camel@freebsd.org> References: <ac7d434f16f3a89f5ef247678d6becdbeded5c3f.camel@freebsd.org> <CE40E2B5-2244-4EF9-B67F-34A54D71E2E8@jeditekunum.com> <f60ea6d2-b696-d896-7bcb-ac628f41f7b8@denninger.net> <20190319161423.GH57400@cicely7.cicely.de> <52df098fdc0caf5de1879c93239534fffbd49b56.camel@freebsd.org> <40f57de2-2b25-3981-a416-b9958cc97636@denninger.net> <669892ac3fc37b0843a156c0ab102316829103fd.camel@freebsd.org> <663f2566-b035-7011-70eb-4163b41e6e55@denninger.net> <20190325164827.GL57400@cicely7.cicely.de> <fc694564b1cf8bfa781ff86a7d5d7d09de68ad0e.camel@freebsd.org>
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On Mon, Mar 25, 2019 at 10:52:26AM -0600, Ian Lepore wrote: > On Mon, 2019-03-25 at 17:48 +0100, Bernd Walter wrote: > > On Mon, Mar 25, 2019 at 11:33:32AM -0500, Karl Denninger wrote: > > > > > > > What do you mean by an insane rate? It's normal for the usb > > > > controller > > > > to be showing around thousands of int/sec. Despite what seems > > > > like a > > > > high rate, even on an on rpi-b it uses under 2% cpu to service > > > > that. > > > > > > > > root@rpi:~ # vmstat -i > > > > interrupt total rate > > > > intc0,2: vchiq0 2 0 > > > > intc0,11: systimer0 10103206 1110 > > > > intc0,17:-x_dwcotg0 218596055 24007 > > > > intc0,28: bcm_dma0 834 0 > > > > intc0,61: iichb0 5778 1 > > > > intc0,65: uart0 1817 0 > > > > intc0,70:-dhci_bcm0 172 0 > > > > Total 228707864 25118 > > > > > > > > -- Ian > > > > > > The story gets more odd. > > > > > > The same *physical* unit that I saw this on last night with no I2c > > > device connected I restarted this morning -- changing NOTHING -- > > > and it > > > disappeared. > > > > > > But -- on another unit it's still there (I haven't shut down, > > > pulled > > > power and restarted that one.) > > > > > > vmstat -i on both doesn't show anything all that odd: > > > misbehaving that's not there, and neither are the missed interrupt > > > complaints. > > > > > > But again, last night the one that this morning is NOT misbehaving > > > WAS, > > > and was showing the exact same thing. > > > > > > So this looks like something that is not being initialized property > > > at > > > boot time, and sometimes however it comes up causes trouble, and > > > other > > > times it does not -- which is likely to make it a "lot" of fun to > > > find. > > > > By causing trouble - do you mean it doesn't work? > > I noticed that my system has this message: > > nxprtc0: RTC clock not running > > Warning: bad time from time-of-day clock, system time will not be set > > accurately > > This shouldn't happen, but I wonder if the iic communication works at > > all. > > I likely wouldn't notice if the rtc failed. > > Maybe there was an initial problem at start as you said. > > Will reboot it and see what happens. > > After a reboot the message about the rtc is gone. > > Have to wait at least a day to see if the Spurious are gone too. > > > > That's not a symptom of i2c comms failure, it's a symptom of a dead rtc > battery. The driver has to communicate with the rtc chip to determine > that the oscillator was stopped. After a reboot all is well, because > the rtc oscillator gets started when the time is written to the chip, > and it keeps running through a reboot and only stops on a power cycle. Agreed, but there is a story behind. The board had a design flaw in that it drained the battery over the pullups into the Pi when the Pi was powered down. I fixed that circuit and did power down tests as well. Don't know if the previous boot was after power down, but it is unlikely that the battery is dead again and if it was a power down then it was a rather short one. It is not a test system, I run it 24/7 as a local ntp server since about only 1-2 months. -- B.Walter <bernd@bwct.de> http://www.bwct.de Modbus/TCP Ethernet I/O Baugruppen, ARM basierte FreeBSD Rechner uvm.
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