śr., 27 lip 2022 o 23:11 Vladimir Oltean <olteanv@xxxxxxxxx> napisał(a):
>
> On Wed, Jul 27, 2022 at 07:40:00PM +0200, Marcin Wojtas wrote:
> > SET_NETDEV_DEV() fills net_device->dev.parent with &pdev->dev
> > and in most cases it is sufficient apparently it is sufficient for
> > fwnode_find_parent_dev_match (at least tests with mvneta case proves
> > it's fine).
>
> Indeed, mvneta works, which is a plain old platform device that hasn't
> even been converted to fwnode, so why don't the others?
>
> Well, as it turns out, it's one of the cases where I spoke to soon,
> thinking I knew what was the problem why probing failed, before actually
> debugging.
>
> I thought there was no dmesg output from DSA at all, which would have
> indicated an eternal -EPROBE_DEFER situation. But there's one tiny line
> I had overlooked:
>
> [ 5.094013] mscc_felix 0000:00:00.5: error -EINVAL: Failed to register DSA switch
>
> This comes from here:
>
> static int dsa_port_parse_fw(struct dsa_port *dp, struct fwnode_handle *fwnode)
> {
> struct fwnode_handle *ethernet = fwnode_find_reference(fwnode, "ethernet", 0);
> bool link = fwnode_property_present(fwnode, "link");
> const char *name = NULL;
> int ret;
>
> ret = fwnode_property_read_string(fwnode, "label", &name);
> // if (ret)
> // return ret;
>
> dp->fwnode = fwnode;
>
> The 'label' property of a port was optional, you've made it mandatory by accident.
> It is used only by DSA drivers that register using platform data.
Thanks for spotting that, I will make it optional again.
>
> (side note, I can't believe you actually have a 'label' property for the
> CPU port and how many people are in the same situation as you; you know
> it isn't used for anything, right? how do we stop the cargo cult?)
>
Well, given these results:
~/git/linux : git grep 'label = \"cpu\"' arch/arm/boot/dts/ | wc -l
79
~/git/linux : git grep 'label = \"cpu\"' arch/arm64/boot/dts/ | wc -l
14
It's not a surprise I also have it defined in the platforms I test. I
agree it doesn't serve any purpose in terms of creating the devices in
DSA with DT, but it IMO increases readability of the description at
least.
> > Can you please check applying following diff:
> >
> > --- a/drivers/base/property.c
> > +++ b/drivers/base/property.c
> > @@ -695,20 +695,22 @@ EXPORT_SYMBOL_GPL(fwnode_get_nth_parent);
> > * The routine can be used e.g. as a callback for class_find_device().
> > *
> > * Returns: %1 - match is found
> > * %0 - match not found
> > */
> > int fwnode_find_parent_dev_match(struct device *dev, const void *data)
> > {
> > for (; dev; dev = dev->parent) {
> > if (device_match_fwnode(dev, data))
> > return 1;
> > + else if (device_match_of_node(dev, to_of_node(data))
> > + return 1;
> > }
> >
> > return 0;
> > }
> > EXPORT_SYMBOL_GPL(fwnode_find_parent_dev_match);
>
> So, nothing to do with device_match_fwnode() failing, that would have
> been strange, come to think about it. Sorry for the noise here.
>
Great, thank you for confirmation.
> But looking at the deeper implementation of dev_fwnode() as:
>
> struct fwnode_handle *dev_fwnode(struct device *dev)
> {
> return IS_ENABLED(CONFIG_OF) && dev->of_node ?
> of_fwnode_handle(dev->of_node) : dev->fwnode;
> }
>
> I wonder, why did you have to modify mvpp2? It looks at dev->of_node
> prior to returning dev->fwnode. It should work.
When I boot with ACPI, the dev->of_node becomes NULL. With DT it's fine as-is.
Best regards,
Marcin
