2023-09-04 15:59:02

by Bjorn Andersson

[permalink] [raw]
Subject: Re: [RFC PATCH v1 00/12] drm,usb/typec: uABI for USB-C DisplayPort connectors

On Mon, Sep 04, 2023 at 12:41:38AM +0300, Dmitry Baryshkov wrote:
> During the discussion regarding DisplayPort wrapped in the USB-C
> connectors (via the USB-C altmode) it was pointed out that currently
> there is no good way to let userspace know if the DRM connector in
> question is the 'native' DP connector or if it is the USB-C connector.
>
> An attempt to use DRM_MODE_CONNECTOR_USB for such connectors was
> declined, as existing DP drivers (i915, AMD) use
> DRM_MODE_CONNECTOR_DisplayPort. New drivers should behave in the same
> way.
>

Sorry, didn't see the commit message before posting my complaint about
USB -> DisplayPort.

> An attempt to use subconnector property was also declined. It is defined
> to the type of the DP dongle connector rather than the host connector.
>
> This attempt targets reusing the connector's PATH property. Currently
> this property is only used for the DP MST connectors. This patchset
> reuses it to point out to the corresponding registered typec port
> device.
>

Still interested in understanding how the path string should look like.

Is the path expected to be consumed by machine, or is it only there for
human convenience?

Regards,
Bjorn