knightly

A queer linux admin that goes "mow"

One of those furries that makes the internets go.
Loves to argue politics, but sometimes doesn't know when to quit.


stillinbeta
@stillinbeta
[763143.794887] usb usb2-port1: attempt power cycle
[763144.130712] usb 3-3: new full-speed USB device number 39 using xhci_hcd
[763144.326815] usb 3-3:  device descriptor read/64, error -71
[763144.630840] usb 3-3:  device descriptor read/64, error -71
[763144.934834] usb 3-3: new full-speed USB device number 40 using xhci_hcd
[763145.130771] usb 3-3:  device descriptor read/64, error -71
[763145.434961] usb 3-3:  device descriptor read/64, error -71
[763145.543092] usb usb3-port3: attempt power cycle
[763146.022958] usb 3-3: new full-speed USB device number 41 using xhci_hcd
[763146.023276] usb 3-3: Device not responding to setup address.
[763146.231278] usb 3-3: Device not responding to setup address.
[763146.438836] usb 3-3:  device not accepting address 41, error -71
[763146.843000] usb 3-3: new full-speed USB device number 42 using xhci_hcd
[763146.843279] usb 3-3: Device not responding to setup address.
[763147.051223] usb 3-3: Device not responding to setup address.
[763147.258932] usb 3-3:  device not accepting address 42, error -71
[763147.259130] usb usb3-port3:  unable to enumerate USB device
[763152.311672] usb usb2-port1:  unable to enumerate USB device

stillinbeta
@stillinbeta

women in STEM hours continue unabated


stillinbeta
@stillinbeta

Finally found the typo that stymied me for the last two weeks heck yeahhhh


stillinbeta
@stillinbeta

i wasn't sure if this probe would work, because it's only rated for 24Mhz and USB FS runs at 12MHz. 2x sampling rate is really the bare minimum, to be safe you want more like 10x. But this looks like a perfectly valid packet. Which is good, because this logic analyzer cost me $20 and a 100+Mhz one costs more like $150


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in reply to @stillinbeta's post:

lol i recently dabbled into usb as well. tried it with an 8051 and a) the docs are shit and b) atmels example implementation did not even work or compile lol

gave up after a while and used an arduino uno (which usually cannot even be used as a usb device except for the serial thingy, but who cares). but yep i know the device descriptor read error too well lol