Date: Mon, 25 Mar 2019 18:09:48 +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: <20190325170948.GN57400@cicely7.cicely.de> In-Reply-To: <20190325170534.GM57400@cicely7.cicely.de> References: <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> <20190325170534.GM57400@cicely7.cicely.de>
next in thread | previous in thread | raw e-mail | index | archive | help
On Mon, Mar 25, 2019 at 06:05:35PM +0100, Bernd Walter wrote: > 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. Well - lets reveal another point. I have removed the pull ups completely, in the assumption that the Pi itself has propper pull ups for at least short wiring. It did work, so I left it that way. So it could indeed be transfer errors by inadequate pull ups causing it. -- B.Walter <bernd@bwct.de> http://www.bwct.de Modbus/TCP Ethernet I/O Baugruppen, ARM basierte FreeBSD Rechner uvm.
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20190325170948.GN57400>