Re: [PATCH v4 00/13] Add ACPI _DSD and unified device properties support

Mark Rutland
2014-10-15T13:15:59Z

On Wed, Oct 15, 2014 at 02:04:31PM +0100, David Woodhouse wrote:
> Here's a completely untested patch to convert of_serial to be usable via
> ACPI properties too. The properties themselves were fairly
> straightforward; the interesting part is converting to
> platform_get_irq() and platform_get_resource() — in the latter case
> first trying IORESOURCE_MEM then IORESOURCE_IO if that fails.
>
> Does this look sane? We'll probably want to think about renaming the
> module and the config option too, but that can come after the basic
> functionality.

The majority of these properties look like they constrained to the
device in question, so make sense for _DSD too.

However...

> @@ -155,7 +168,7 @@ static int of_platform_serial_probe(struct platform_device *ofdev)
> if (!match)
> return -EINVAL;
>
> - if (of_find_property(ofdev->dev.of_node, "used-by-rtas", NULL))
> + if (!device_get_property(&ofdev->dev, "used-by-rtas", NULL))
> return -EBUSY;

This property should never be present on an ACPI system. RTAS is a
completely different firmware interface on PowerPC.

As a general note, I would hope that we're not going to blindly convert
drivers and subsystems over to a common property interface without
considering each property w.r.t. the particular FW interface.

Each addition to _DSD, especially if through a common accessor needs
_more_ scrutiny than is applied to DT bindings, and we hardly manage to
review DT bindings.

Mark.
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