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SubjectRe: earlyprintk=xdbc seems broken
On 1/25/22 05:09, Sven Schnelle wrote:
>> Now the documentation states we need this super speed A<->A cable, but
>> could you also update the documentation for usb-c ? There's a fair
>> number of usb-c only devices out there now.
> Stupid beginners question: Would every USB3 A-A cable work, or are the
> debug cables special? I've read the RX/TX pairs have to be swapped, but
> to me it looks like that's always the case?

My understanding is that the 5v line is disconnected. Here's one cable
I have:

> https://designintools.intel.com/SVT_DCI_DbC2_3_A_to_A_Debug_Cable_1_Meter_p/itpdciamam1m.htm

I think they snip that line to prevent any chance of current flowing
between devices. The cable isn't expensive, but I do remember being
astounded at how much Intel charged itself for shipping it. ;)

That said, I've also used the same cable Peter has: just a cheap A-to-A
cable I had lying around. It surely has VBUS connected, so I usually
plumb it through a USB hub with a power switch. This surely isn't the
"right" way to do it, but it does seem to work in some situations.

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