On Tue, Jul 13, 2021 at 11:18 PM Martin Kepplinger
<martin.kepplinger@xxxxxxx> wrote:
>
> Similar as with tcpm this patch lets fw_devlink know not to wait on the
> fwnode to be populated as a struct device.
>
> Without this patch, USB functionality can be broken on some previously
> supported boards.
>
> Fixes: 28ec344bb891 ("usb: typec: tcpm: Don't block probing of consumers of "connector" nodes")
> Signed-off-by: Martin Kepplinger <martin.kepplinger@xxxxxxx>
> ---
>
> revision history
> ----------------
> v2: (thank you Saravana)
> * add a code-comment why the call is needed.
>
> v1:
> https://lore.kernel.org/linux-usb/20210713073946.102501-1-martin.kepplinger@xxxxxxx/
>
>
>
> drivers/usb/typec/tipd/core.c | 9 +++++++++
> 1 file changed, 9 insertions(+)
>
> diff --git a/drivers/usb/typec/tipd/core.c b/drivers/usb/typec/tipd/core.c
> index 938219bc1b4b..21b3ae25c76d 100644
> --- a/drivers/usb/typec/tipd/core.c
> +++ b/drivers/usb/typec/tipd/core.c
> @@ -629,6 +629,15 @@ static int tps6598x_probe(struct i2c_client *client)
> if (!fwnode)
> return -ENODEV;
>
> + /*
> + * This fwnode has a "compatible" property, but is never populated as a
> + * struct device. Instead we simply parse it to read the properties.
> + * This breaks fw_devlink=on. To maintain backward compatibility
> + * with existing DT files, we work around this by deleting any
> + * fwnode_links to/from this fwnode.
> + */
> + fw_devlink_purge_absent_suppliers(fwnode);
> +
Hey Martin,
As part of a series I'm working on, I'm looking into deleting
fw_devlink_purge_absent_suppliers() and having the driver core figure
this out automatically.
So I was making sure all the current uses of
fw_devlink_purge_absent_suppliers() would automatically be handled by
driver core. But when I looked at this usage of
fw_devlink_purge_absent_suppliers(), I didn't see any "compatible"
property in the "connector" child node. So, I'm confused how you had a
problem without this patch.
fw_devlink would have created fwnode links
between typec_pd and usb_dwc3_0, figured out it's a cycle and have
stopped enforcing the "remote-endpoint" dependencies.
Can you give me more details please on why you were having a problem
without this patch?
I'm looking at arch/arm64/boot/dts/freescale/imx8mq-librem5.dtsi as an
example because you listed it in your v1 patch.
-Saravana
> tps->role_sw = fwnode_usb_role_switch_get(fwnode);
> if (IS_ERR(tps->role_sw)) {
> ret = PTR_ERR(tps->role_sw);
> --
> 2.30.2
>
