[PATCH v2] drm/bridge: Fix assignment of the of_node of the parent to aux bridge

Sui Jingfeng sui.jingfeng at linux.dev
Fri Nov 1 03:49:07 UTC 2024


On 2024/11/1 00:23, Johan Hovold wrote:
> On Thu, Oct 31, 2024 at 11:06:38PM +0800, Sui Jingfeng wrote:
>
>> But I think Johan do need more times to understand what exactly
>> the real problem is. We do need times to investigate new method.
> No, I know perfectly well what the (immediate) problem is here (I was
> the one adding support for the of_node_reused flag some years back).
>
> I just wanted to make sure that the commit message was correct and
> complete before merging (and also to figure out whether this particular
> patch needed to be backported).


Well under such a design, having the child device sharing the 'OF' device
node with it parent device means that one parent device can *only*
create one AUX bridge child device.

Since If you create two or more child AUX bridge, *all* of them will
call devm_drm_of_get_bridge(&auxdev->dev, auxdev->dev.of_node, 0, 0),
then we will *contend* the same next bridge resource.

Because of the 'auxdev->dev.of_node' is same for all its instance.
While other display bridges seems don't has such limitations.


> Johan

-- 
Best regards,
Sui



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