From mboxrd@z Thu Jan 1 00:00:00 1970 From: Toshi Kani Subject: Re: [Patch v1 1/3] ACPI: add callback prepare() into acpi_hotplug_handler Date: Tue, 21 Jan 2014 16:06:36 -0700 Message-ID: <1390345596.1792.468.camel@misato.fc.hp.com> References: <1390013297-23462-1-git-send-email-jiang.liu@linux.intel.com> <1390338897.1792.467.camel@misato.fc.hp.com> <2201697.uqWgsYrLat@vostro.rjw.lan> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <2201697.uqWgsYrLat@vostro.rjw.lan> Sender: linux-pci-owner@vger.kernel.org To: "Rafael J. Wysocki" Cc: Jiang Liu , "Rafael J . Wysocki" , Bjorn Helgaas , Yinghai Lu , Yijing Wang , Len Brown , Robert Moore , Lv Zheng , linux-acpi@vger.kernel.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, devel@acpica.org List-Id: linux-acpi@vger.kernel.org On Wed, 2014-01-22 at 00:17 +0100, Rafael J. Wysocki wrote: > On Tuesday, January 21, 2014 02:14:57 PM Toshi Kani wrote: > > On Sat, 2014-01-18 at 10:48 +0800, Jiang Liu wrote: > > > Add callback prepare() into acpi_hotplug_handler, which will get called > > > at the very beginning of ACPI hotplug event handler. The ACPI core will > > > ignore the event if prepare() returns NOTIFY_STOP. > > > > > > Signed-off-by: Jiang Liu > > > --- > > > drivers/acpi/scan.c | 4 ++++ > > > include/acpi/acpi_bus.h | 1 + > > > 2 files changed, 5 insertions(+) > > > > > > diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c > > > index fd39459..6b0f419 100644 > > > --- a/drivers/acpi/scan.c > > > +++ b/drivers/acpi/scan.c > > > @@ -392,6 +392,10 @@ static void acpi_hotplug_notify_cb(acpi_handle handle, u32 type, void *data) > > > struct acpi_device *adev; > > > acpi_status status; > > > > > > + if (handler->prepare && > > > + handler->prepare(handle, type, data) == NOTIFY_STOP) > > > + return; > > > > The OS is responsible for calling _OST when it is implemented. So you > > cannot just return here. See acpi_hotplug_unsupported(handle, type) > > next line. Also, please describe why prepare() needs to be added. > > I don't think it's needed any more, please see: > > http://marc.info/?l=linux-acpi&m=139001691317575&w=2 Oh, I see. Thanks! -Toshi