Hacker News Reader

Comment by nimish | Hacker News Reader

Will most likely lead to Nintendo Switch style situations where the physical port is USB-C but in actuality it uses a proprietary charger. Now they can lock out third party docks/chargers.

Not a great situation.

View on HN

The Nintendo Switch actually uses USB-C power delivery, and from everything I can tell, the link between the power supply and the official Nintendo dock is compliant. Using third party docks, or trying to power the switch from the bottom connector does seem to be a little dicier.

The issues people have had with it seem to be that the Switch dock requests exactly 15V from the power supply when plugged into a TV, and many USB-C power supplies don't support this voltage. The MacBook pro charger supports 9 and 20V (I think), and most others use 9, 12, or 20.

The problem is that there's no indication of what failed unless you're sniffing the power delivery handshake.

My first thought too. Every standard seems to eventually add DRM-ish features if it's been around long enough. This won't stop maliciousness/determined attackers, but instead it will just become another hurdle of proprietariness that restricts users unnecessarily while protecting the profits of the big companies.

(Of course, it's always done "for your security"...)

Was this applied in a later software update? I distinctly recall using my Thinkpad's charger with my Switch, prior to giving it to a friend.

edit: Keep in mind that a charger meant for a phone is unlikely to provide anywhere enough power for the Switch. You likely need a charger that implements at least USB-C PD.

The issue specifically arises when using third-party chargers and/or docks with the system docked. In docked mode, the Switch draws more power than when undocked, and requests an amount of power which is not the same as the amount of power that it actually expects, or that is delivered by the first-party charger and dock. This can result in bricking your system.

In short, the Switch does not properly implement the USB-PD standard.

I read that the situation is more nuanced than that. The Switch requests more power than expected because USB devices plugged into the dock might use a lot of power. So it needs to make sure enough power is available just in case.

I've heard that third-party chargers work. I could be wrong though.

The problem is that the Switch isn't to spec in regards to how it negotiates power. It generally isn't a problem, but some third-party docks would toast your Switch because of it.

There's a nice write-up of the USB spec violations done by the Switch: https://plus.google.com/102612254593917101378/posts/2CUPZ5yV...

It is not like you couldn't do crypto handshakes before this if you wanted to lock down your system. Now it is just standardized.

It'll be incredibly frustrating to have to think about which USB-C device is compatible with which. You want to make a proprietary charger? Use a custom connector and stop confusing end users.

HP at least was already doing it on their laptops. Though at least some models later disabled the lock with BIOS updates.

My HP Spectre won't charge from non-HP usb-c chargers in Windows; or, at least, it complains and says it won't charge. I haven't tested whether it actually draws current or not since I only booted it once in Windows. However, in Linux it charges fine at full-speed from non-HP charger with appropriate wattage. It will not charge at all from several chargers that don't have the necessary 90W capability.

Reply on news.ycombinator.com