On Wednesday 27 November 2019 07:11:26 Reco wrote: > On Wed, Nov 27, 2019 at 07:03:13AM -0500, Gene Heskett wrote: > > On Wednesday 27 November 2019 01:55:50 Reco wrote: > > > Hi. > > > > > > On Tue, Nov 26, 2019 at 05:05:13PM -0500, Gene Heskett wrote: > > > > Greetings all; > > > > > > > > I have what I believe to be noise or crosstalk causing > > > > interference between a wireless keyboard mouse and the machine > > > > they are controlling, which is an rpi4. The app itself doesn't > > > > expose any usb traffic to the user. The effect is as if the > > > > finger was lifted from the key for a hundred ms or so at random > > > > intervals. > > > > > > > > So what, on an armhf raspi, do we have for a usbsnoop? > > > > > > /usr/sbin/tcpdump -D > > > > > > </thread> > > > > Thanks Reco, I had to install it, but then reread the man page a > > couple times, but I don't get it yet: (screen snip) > > tcpdump(8) says: > > -i interface > --interface=interface > Listen on interface ... > If the -D flag is supported, an interface number as printed by > that flag can be used as the interface argument, if no interface on > the system has that number as a name. > > So, > > sudo /usr/sbin/tcpdump -i 8 > > Reco
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 pi@rpi4:~/linuxcnc/configs/sheldon-lathe $ sudo ls /sys/kernel/debug asoc cleancache devices_deferred f2fs hid memblock pm_genpd regmap sleep_time vc-mem bdi clear_warn_once dma_buf fault_around_bytes ieee80211 mmc0 pm_qos regulator tracing vcsm-cma block clk dri frontswap irq mmc1 pwm sched_debug usb vc-smem bluetooth device_component extfrag gpio kprobes pinctrl ras sched_features vchiq Thanks anyway, Reco. 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>
