[PATCH v5 2/8] usb: dwc3: of-simple: bail probe if no dwc3 child node

[Heiko Stübner]

Hi Greg, Felipe,

Am Dienstag, 9. Februar 2021, 20:23:44 CET schrieb Johan Jonker:
> For some of the dwc3-of-simple compatible SoCs we
> don't want to bind this driver to a dwc3 node,
> but bind that node to the 'snps,dwc3' driver instead.
> The kernel has no logic to decide which driver to bind
> to if there are 2 matching drivers, so bail probe if no
> dwc3 child node.
> 
> Signed-off-by: Johan Jonker <jbx6244 at gmail.com>

It looks like this patch fell through the cracks?

I.e. I can see patches 1+6 adding the devicetree bindings
in 5.12-rc but haven't found this patch there.

And looking at
https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git/log/drivers/usb/dwc3/dwc3-of-simple.c?h=usb-next
I also didn't find it.

>From what I gathered that was somehow mandated from the Devicetree side
as the dwc3-subnode system merely is some Linux-specific thingy
and should not be enforced if not explicitly needed.

I guess Johan can provide pointers to the previous discussion.

So could you look at applying this patch to some usb-tree?


Thanks
Heiko


> ---
>  drivers/usb/dwc3/dwc3-of-simple.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/usb/dwc3/dwc3-of-simple.c b/drivers/usb/dwc3/dwc3-of-simple.c
> index e62ecd22b..347b4d384 100644
> --- a/drivers/usb/dwc3/dwc3-of-simple.c
> +++ b/drivers/usb/dwc3/dwc3-of-simple.c
> @@ -38,6 +38,10 @@ static int dwc3_of_simple_probe(struct platform_device *pdev)
>  
>  	int			ret;
>  
> +	/* Bail probe if no dwc3 child node. */
> +	if (!of_get_compatible_child(dev->of_node, "snps,dwc3"))
> +		return -ENODEV;
> +
>  	simple = devm_kzalloc(dev, sizeof(*simple), GFP_KERNEL);
>  	if (!simple)
>  		return -ENOMEM;
>