Re: [PATCHv13 2/3] usb: USB Type-C connector class

From: Oliver Neukum
Date: Wed Dec 07 2016 - 04:53:28 EST


On Fri, 2016-12-02 at 10:04 -0800, Guenter Roeck wrote:

Hi,

> At least for my part I very much concentrated on making sure that
> the user space ABI as well as the port driver API are sane and usable.

Rightly so, as this part cannot be changed once included in a kernel
release.
So, can we agree that that part at least is ready to go?

> The driver interface is not my area of expertise. As such, my testing
> and understanding of that part was limited to "it appears to work,
> it must be ok". I very much relied on you to get this part right.
>
> That makes me feel really bad. It isn't fun to have my "Reviewed-by"
> on a patch that gets (and apparently deserves) a WTF from a senior
> kernel maintainer. This hurts both your and my reputation, and obviously
> will make me quite hesitant to add a "Reviewed-by:" to the next version
> of the series.

The driver model is arcane. It is the reason we have people who really
understand it review code.

But I think it is a reason we need to question assumptions.
Is it really true that the lifetimes of both ends of a plug
are tightly locked? What happens if you unplug a cable
whose ends have different power supplies?

Regards
Oliver