# Re: \[PATCH v8 02/16\] device property: Add fwnode\_graph\_get\_next\_port\_endpoint()

- From: Sakari Ailus \<sakari.ailus@linux.intel.com\>
- Date: 2026-09-04 20:22:45 
- List: linux-arm-kernel
- Page: https://ratatoskr.run/linux-arm-kernel/2026/09/17516716
- Thread: https://ratatoskr.run/linux-acpi/2026/09/17512168/t.md

```text
On Fri, Sep 04, 2026 at 04:41:41PM +0800, Chen-Yu Tsai wrote:
> Due to design constraints of the power sequencing API, the consumer
> must first be sure that the other side is actually a provider, or it
> will continually get -EPROBE_DEFER when requesting the power
> sequencing descriptor.
> 
> In the upcoming USB power sequencing integration, the USB hub driver
> first needs to check whether a graph connection exists, and whether
> the other side of the connection is a supported connector type. The
> USB port is tied to a "port" firmware node, and this new helper will
> be used to get the endpoint under the known "port" firmware node.
> 
> Sashiko points out that the |prev| reference put is not done if |port|
> is NULL. However it seems that the fwnode_*() and of_*() API design
> implicitly makes the functions no-ops if the passed in node is NULL.
> So this new addition follows the same pattern.

I'd put this last paragraph after the '---' line.

> 
> Cc: Sakari Ailus <sakari.ailus@linux.intel.com>
> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> Reviewed-by: Bartosz Golaszewski <redacted>
> Signed-off-by: Chen-Yu Tsai <wenst@chromium.org>

Reviewed-by: Sakari Ailus <sakari.ailus@linux.intel.com>

-- 
Sakari Ailus

```