Re: [RFC PATCH 6/8] ACPI: use platform bus as the default bus for _HID enumeration

Rafael J. Wysocki
2014-03-02T23:36:08Z

On Wednesday, February 26, 2014 05:11:12 PM Zhang Rui wrote:
> Because of the growing demand for enumerating ACPI devices to platform bus,
> this patch changes the code to enumerate ACPI devices with _HID/_CID to
> platform bus by default, unless the device already has a scan handler attached.
>
> Signed-off-by: Zhang Rui <rui.zhang@intel.com>
> ---
> drivers/acpi/acpi_platform.c | 28 ----------------------------
> drivers/acpi/scan.c | 12 ++++++------
> 2 files changed, 6 insertions(+), 34 deletions(-)
>
> diff --git a/drivers/acpi/acpi_platform.c b/drivers/acpi/acpi_platform.c
> index dbfe49e..33376a9 100644
> --- a/drivers/acpi/acpi_platform.c
> +++ b/drivers/acpi/acpi_platform.c
> @@ -22,24 +22,6 @@
>
> ACPI_MODULE_NAME("platform");
>
> -/*
> - * The following ACPI IDs are known to be suitable for representing as
> - * platform devices.
> - */
> -static const struct acpi_device_id acpi_platform_device_ids[] = {
> -
> - { "PNP0D40" },
> - { "ACPI0003" },
> - { "VPC2004" },
> - { "BCM4752" },
> -
> - /* Intel Smart Sound Technology */
> - { "INT33C8" },
> - { "80860F28" },
> -
> - { }
> -};
> -
> /**
> * acpi_create_platform_device - Create platform device for ACPI device node
> * @adev: ACPI device node to create a platform device for.
> @@ -125,13 +107,3 @@ int acpi_create_platform_device(struct acpi_device *adev,
> kfree(resources);
> return 1;
> }
> -
> -static struct acpi_scan_handler platform_handler = {
> - .ids = acpi_platform_device_ids,
> - .attach = acpi_create_platform_device,
> -};
> -
> -void __init acpi_platform_init(void)
> -{
> - acpi_scan_add_handler(&platform_handler);
> -}
> diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
> index 5967338..61af32e 100644
> --- a/drivers/acpi/scan.c
> +++ b/drivers/acpi/scan.c
> @@ -2022,14 +2022,15 @@ static int acpi_scan_attach_handler(struct acpi_device *device)
> handler = acpi_scan_match_handler(hwid->id, &devid);
> if (handler) {
> ret = handler->attach(device, devid);
> - if (ret > 0) {
> + if (ret > 0)
> device->handler = handler;
> - break;
> - } else if (ret < 0) {
> - break;
> - }
> + if (ret)
> + goto end;
> }
> }
> +end:
> + if (!list_empty(&device->pnp.ids) && !device->handler)

I'm a bit concerned that this check will create platform devices for too many
ACPI device objects. Shouldn't we require that _HID or at least _CID is
present for that?

> + acpi_create_platform_device(device, NULL);
> return ret;
> }
>
> @@ -2185,7 +2186,6 @@ int __init acpi_scan_init(void)
> acpi_pci_root_init();
> acpi_pci_link_init();
> acpi_processor_init();
> - acpi_platform_init();
> acpi_lpss_init();
> acpi_cmos_rtc_init();
> acpi_container_init();
>

--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.