> -----Original Message----- > From: Rafael J. Wysocki [mailto:r...@rjwysocki.net] > Sent: Tuesday, March 04, 2014 7:23 AM > To: Zhang, Rui > Cc: linux-a...@vger.kernel.org; linux-kernel@vger.kernel.org; > bhelg...@google.com; matthew.garr...@nebula.com; Wysocki, Rafael J; > dmitry.torok...@gmail.com > 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.zh...@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. > > > > 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... Thanks, rui > Rafael
