netdev - Re: [PATCH v2 04/16] ACPI: property: Return present device nodes only on fwnode interface

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Message-ID: <20250929103558.000033bf@huawei.com>
Date: Mon, 29 Sep 2025 10:35:58 +0100
From: Jonathan Cameron <jonathan.cameron@...wei.com>
To: Sakari Ailus <sakari.ailus@...ux.intel.com>
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Subject: Re: [PATCH v2 04/16] ACPI: property: Return present device nodes
 only on fwnode interface

On Wed, 24 Sep 2025 10:45:50 +0300
Sakari Ailus <sakari.ailus@...ux.intel.com> wrote:

> fwnode_graph_get_next_subnode() may return fwnode backed by ACPI device
> nodes and there has been no check these devices are present in the system,
> unlike there has been on fwnode OF backend. In order to provide consistent
> behaviour towards callers, add a check for device presence by introducing
> a new function acpi_get_next_present_subnode(), used as the
> get_next_child_node() fwnode operation that also checks device node
> presence.
> 
> Signed-off-by: Sakari Ailus <sakari.ailus@...ux.intel.com>

I think this is fine because of the bit in the ACPI spec that says all
bits are set if _STA is missing.   It seems much less likely we'll see
problems with hardware disappearing because _STA is there but says
the device isn't present.

Always a regression risk though :(

With the formatting changes Laurent asked for
Reviewed-by: Jonathan Cameron <jonathan.cameron@...wei.com>