On Fri, 2014-03-07 at 02:46 +0100, Rafael J. Wysocki wrote: > On Tuesday, March 04, 2014 01:35:00 AM Rafael J. Wysocki wrote: > > On 3/4/2014 1:27 AM, Zhang, Rui wrote: > > > > > >> -----Original Message----- > > >> From: Rafael J. Wysocki [mailto:rjw@xxxxxxxxxxxxx] > > >> Sent: Tuesday, March 04, 2014 7:23 AM > > >> To: Zhang, Rui > > >> Cc: linux-acpi@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; > > >> bhelgaas@xxxxxxxxxx; matthew.garrett@xxxxxxxxxx; Wysocki, Rafael J; > > >> dmitry.torokhov@xxxxxxxxx > > >> Subject: Re: [RFC PATCH 6/8] ACPI: use platform bus as the default bus > > >> for _HID enumeration > > >> Importance: High > > >> > > >> On Monday, March 03, 2014 10:11:48 PM Zhang Rui wrote: > > >>> On Mon, 2014-03-03 at 00:51 +0100, Rafael J. Wysocki wrote: > > >>>> 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@xxxxxxxxx> > > >>>>> --- > > >>>>> 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. > > >>> agreed. there are some devices created unexpected by this patch, e.g. > > >>> on my test machine, I can see > > >>> > > >>> /sys/bus/platform/devices/LNXSYSTM:00 (ACPI system bus/root node) > > >>> /sys/bus/platform/devices/PNP0000:00 (PIC) > > >>> /sys/bus/platform/devices/PNP0100:00 (system timer?) > > >>> > > >>>> Shouldn't we require that _HID or at least _CID is present for > > >>>> that? > > >>>> > > >>> I do not think so. > > >>> only devices that invoke acpi_add_ids() may have pnp.ids but no > > >>> _HID/_CID, right? > > >>> I did a check in the code, those devices include: > > >> Well, I did that too. > > >> > > >>> ACPI root node > > >>> ACPI video > > >>> ACPI bay > > >>> ACPI dock > > >>> IBM SMBus > > >>> ACPI Power resource > > >>> ACPI processor > > >>> ACPI thermal > > >>> ACPI fixed power/sleep button > > >>> > > >>> IMO, only the ACPI root node, ACPI power resource, possibly ACPI > > >>> processor are the ones that we do not want to see in platform bus. > > >> No, we don't want any of them. So pretty much as I said, only if > > >> _HID/_CID is present, please? > > >> > > > Why? We will convert the drivers for most of those devices from ACPI bus to platform bus sooner or later. > > > We need to see them in platform bus... > > > > No, we don't. > > > > I'm not sure about IBM SMBus to be honest, but as for the rest: > > > > Why would we want one for the ACPI root? > > > > And for video? Those things are PCI usually devices anyway and we just > > add "artificial" HIDs for them. > > > > ACPI docks and bays are handled by the dock driver which creates > > platform devices for them already if needed and we don't want duplicates > > there. > > > > ACPI processor has its own scan handler that binds those objects to > > system devices. > > > > Power resources - no need. > > > > Do we need platform devices for ACPI thermal zones? > > > > Yes, we will need them for fixed buttons, but that's a special case anyway. > > So, why don't we add an ACPI device object flag, say hid_device, such that if > set, the ACPI core will create a struct platform device for that device object. > Then, we can set hid_device for buttons and other stuff we care about. > agreed. I will do this in next version. But anyway, the exclude list is still needed for the _HID devices that we do not want to see in platform, e.g. /sys/bus/platform/devices/PNP0000:00 (PIC) /sys/bus/platform/devices/PNP0100:00 (system timer?) thanks, rui > Thanks, > Rafael > -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
