Re: [PATCH 0/4] Convert ACPI fan driver to platform driver

From: Rafael J. Wysocki
Date: Thu Dec 05 2013 - 16:49:10 EST


On Thursday, December 05, 2013 03:47:35 PM Aaron Lu wrote:
> On Thu, Dec 05, 2013 at 12:07:31AM +0100, Rafael J. Wysocki wrote:
> > On Tuesday, December 03, 2013 04:28:28 PM Aaron Lu wrote:
> > > This patchset converts ACPI fan driver to platform driver. Patch 1-3 are
> > > cleanups for existing fan driver and patch 4 does the convertion.
> > >
> > > Tested on harris beach.
> > > Apply on top of Rafael's linux-next branch.
> > >
> > > Aaron Lu (4):
> > > ACPI / fan: remove unused macro for debug
> > > ACPI / fan: remove no need check for device pointer
> > > ACPI / fan: use acpi_device_xxx_power instead of acpi_bus equivelant
> > > ACPI / fan: convert to platform driver
> > >
> > > drivers/acpi/acpi_platform.c | 3 ++
> > > drivers/acpi/device_pm.c | 1 +
> > > drivers/acpi/fan.c | 88 ++++++++++++++++----------------------------
> > > drivers/acpi/internal.h | 2 -
> > > include/acpi/acpi_bus.h | 1 +
> > > 5 files changed, 36 insertions(+), 59 deletions(-)
> >
> > Unfortunately, we need to postpone these conversions, because Matthew Garrett
> > has problems with adding more entries to acpi_platform_device_ids[]. He seems
> > to be concerned that that list will grow indefinitely and will become difficult
> > to maintain eventually.
> >
> > For this reason, he would prefer it if we did the following:
> > - Figure out the list of ACPI device IDs we need to create PNP devices for
> > via ACPI PNP.
>
> I'm not sure how to tell this, is it that as long as the ACPI node has a
> PNPxxxx ID we will need to create a PNP device for it? And in this case,
> do we only check the _HID or both _HID and _CID?

Just check the existing PNP drivers and see what device IDs they use.

> > - Make ACPI PNP create PNP devices for these IDs only and make the ACPI core create
> > platform devices for all "unassigned" ACPI device objects by default.
>
> Does "unassigned" mean (all ACPI devices) - (ACPI devices that have a
> PNP device created already)?

(all ACPI devices nodes) - (nodes taken care of by scan handlers + PNP)
(and I *think* we can turn the PNP ACPI driver into a scan handler).

Thanks,
Rafael

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