[PATCH 12/18] drm/sysfb: ofdrm: Add EDID support

[Maxime Ripard]

On Thu, Mar 20, 2025 at 02:08:56PM +0100, Thomas Zimmermann wrote:
> > Despite the nitpicks, overall LGTM.
> 
> Thanks for reviewing.
> 
> Since I have your attention and you're knowledgeable wrt EDID: byte 20 of
> the EDID header indicates the type of output (analog, HDMI, DP, etc). I
> intent to use this for setting the connector type to something better then
> UNKNOWN. Does that make sense?

I don't think it would work:

  - EDID doesn't indicate the kind of KMS output (ie, source) but the
    type of sink. Ie, what the monitor is capable of dealing with, not
    what the connector can emit. If we have (passive or active) bridges
    in between, it does mean that we can have an analog sink connected
    to a digital connector.

  - Since it depends on the sink, it can change over time, ie you plug
    an analog monitor, remove it, and plug a digital one. That would
    mean changing the connector type (and thus name exposed to
    userspace) at runtime, for the same driver.

  - Since it depends on the sink, it assumes the sink vendor didn't
    botch the EDID. This one is a pretty big if :)

Maxime
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