On Wednesday 27 November 2019 12:50:37 Gene Heskett wrote: > On Wednesday 27 November 2019 08:41:38 to...@tuxteam.de wrote: > > On Wed, Nov 27, 2019 at 08:22:25AM -0500, Gene Heskett wrote: > > > > [...] > > > > > Doesn't look as if it will work with this preempt-rt kernel :( > > > > > > pi@rpi4:~/linuxcnc/configs/sheldon-lathe $ sudo /usr/sbin/tcpdump > > > -i 7 tcpdump: Can't open USB bus file /sys/kernel/debug/usbmon/1t: > > > No such file or directory > > > > Throwing the error message into a search engine yields some > > promising links: > > > > > > https://stackoverflow.com/questions/32740413/no-usb-bus-file-even-af > >te r-enabling-usbmon-in-android-kernel > > https://unix.stackexchange.com/questions/546719/no-such-file-or-dire > >ct ory-sys-kernel-debug-usb-usbmon > > > > So it seems you need the usbmon module loaded (is it?) > > no, is now. And watching the 3 choices for more than enough time to > see several of these "noise events" if that what it is, gets this: > pi@rpi4:~/linuxcnc/configs/sheldon-lathe $ sudo /usr/sbin/tcpdump -i > 8 tcpdump: verbose output suppressed, use -v or -vv for full protocol > decode > listening on usbmon1, link-type USB_LINUX_MMAPPED (USB with padded > Linux header), capture size 262144 bytes > 12:07:06.611219 CONTROL SUBMIT to 1:17:0 > 12:07:06.613656 CONTROL COMPLETE from 1:17:0 > 12:07:06.613861 CONTROL SUBMIT to 1:16:0 > 12:07:06.615532 CONTROL COMPLETE from 1:16:0 > 12:07:06.615886 CONTROL SUBMIT to 1:3:0 > 12:07:06.616363 CONTROL COMPLETE from 1:3:0 > 12:07:06.616506 CONTROL SUBMIT to 1:2:0 > 12:07:06.616766 CONTROL COMPLETE from 1:2:0 > 12:07:06.616882 CONTROL SUBMIT to 1:1:0 > 12:07:06.616924 CONTROL COMPLETE from 1:1:0 > ^C > 10 packets captured > 10 packets received by filter > 0 packets dropped by kernel > pi@rpi4:~/linuxcnc/configs/sheldon-lathe $ sudo /usr/sbin/tcpdump -i > 9 -v > tcpdump: listening on usbmon2, link-type USB_LINUX_MMAPPED (USB with > padded Linux header), capture size 262144 bytes > 12:09:50.820947 CONTROL SUBMIT to 2:3:0 > 12:09:50.821114 CONTROL COMPLETE from 2:3:0 > 12:09:50.821365 CONTROL SUBMIT to 2:2:0 > 12:09:50.821512 CONTROL COMPLETE from 2:2:0 > 12:09:50.821699 CONTROL SUBMIT to 2:1:0 > 12:09:50.821737 CONTROL COMPLETE from 2:1:0 > ^C > 6 packets captured > 6 packets received by filter > 0 packets dropped by kernel > pi@rpi4:~/linuxcnc/configs/sheldon-lathe $ sudo /usr/sbin/tcpdump -i > 10 -vv > tcpdump: listening on usbmon3, link-type USB_LINUX_MMAPPED (USB with > padded Linux header), capture size 262144 bytes > 12:10:46.640549 CONTROL SUBMIT to 3:1:0 > 12:10:46.640597 CONTROL COMPLETE from 3:1:0 > ^C > 2 packets captured > 2 packets received by filter > 0 packets dropped by kernel > pi@rpi4:~/linuxcnc/configs/sheldon-lathe $ > > > and > > the debugfs pseudo file system mounted (again, is it?). > > No. Each of the above captures was presented within 2 secs of the > invocation, followed by silence, so I get the impression I'm barking > up the wrong tree and should look elsewhere for the cause of the > motion stutter. This app, linuxcnc, has an o-scope like facility with > very limited sampling to aid in signal tracing, limited because it > only runs once per thread invocation, and since I am useing Mesa fpga > based interface cards which take over the need for 20 microsecond > controls, the remaining thread invoc's are at 1ms or even 5ms > intervals for the jog dials I've installed to replace the manual > cranks it had 70 years ago. Those signals I can see, but the manual > signals, like from the arrow keys on the keyboard, are all hidden, not > available to be seen by this "scope", going thru a bunch of steering > stuff before getting to the actual joint circuitry as a move a motor > command. > > The app itself has an 8 digit debug control, but I haven't found a > definition of which of those 32 bits enables what debugging traces. > We have several Docs, the main one being over 800 pages, so I have > some concentrated reading to do. > > Thanks muchly for the help Reco, its appreciated, a lot. I think it > pretty much rules out local rfi as a source of this problem so I must > figure out how to look elsewhere. > > > HTH > > -- tomás > And I see I'm replying to two helpers, my apologies, Tomas, for leaving out your contribution, thank you, a bunch.
> Cheers, Gene Heskett Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) If we desire respect for the law, we must first make the law respectable. - Louis D. Brandeis Genes Web page <http://geneslinuxbox.net:6309/gene>