
How to design a proper USB-C power sink (not the way Raspberry Pi 4 did it) - sohkamyung
https://people.kernel.org/bleung/how-to-design-a-proper-usb-c-power-sink-hint-not-the-way-raspberry-pi-4
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ggm
Eben is usually responsive. I would love pointers to any acknowledgement this
is a correct analysis.

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sohkamyung
Benson Leung (the author of the post) was well known for analysing various
USB-C products (cables, etc.) and posting critiques of them on Google+.

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ggm
Yes, I subscribed to his g+ channel. It's because he did such a good job I am
interested in Eben acknowledging the underlying correctness of Benson's
analysis.

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sohkamyung
Update: apparently Eben has acknowledge the issue and is to be fixed in a
future update [1]:

 _Following reports of certain USB-C cables not working with the Pi 4, the Pi
's co-creator Eben Upton has confirmed that not every USB-C cable will power
the Pi._

[...]

 _" A smart charger with an e-marked cable will incorrectly identify the
Raspberry Pi 4 as an audio adapter accessory, and refuse to provide power,"
says Upton._

 _" I expect this will be fixed in a future board revision, but for now users
will need to apply one of the suggested workarounds. It's surprising this
didn't show up in our (quite extensive) field testing program."_

[1] [https://www.techrepublic.com/article/your-new-raspberry-
pi-4...](https://www.techrepublic.com/article/your-new-raspberry-pi-4-wont-
power-on-usb-c-cable-problem-now-officially-confirmed/)

~~~
ggm
Came here to post the same. Good for him! well done.

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sunstone
It's all fun and games until you go into production.

