[PATCH 2/6] drm/bridge: tc358775: Fix getting dsi host data lanes

Michael Walle mwalle at kernel.org
Mon Nov 27 14:31:44 UTC 2023


+ dt maintainers

>> I actually have the same fix, but with one additional detail, which 
>> I'm
>> unsure about though: This looks at the data-lanes property of the 
>> *remote*
>> endpoint whereas other bridge drivers (see tc358767, ti-sn65dsi83, 
>> lt8912b,
>> anx7625) look at the local endpoint and I'm not sure what is correct.
> 
> Yes I've been wondering about that too. Let's just move it over to the
> bridge node? We could produce a warning if the dsi host node has the
> data-lanes property.. No current in kernel users AFAIK.

I haven't found any in-tree users either. In my patch, I first try the 
remote
end and then the local end. But thinking more about it I don't think
this is correct. Maybe we can do it the other way around, first try
data-lanes of the local endpoint and if not found, then try the remote
one. That way, we would at least be backwards compatible in the driver.
And for the dt-bindings, make it mandatory to have a local data-lanes.

-michael

> FYI, for omapdrm, we already have a legacy dt property "lanes" for the
> wiring that tells number of lanes used and the order of the lanes.
> 
> Regards,
> 
> Tony


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