From mboxrd@z Thu Jan 1 00:00:00 1970 From: Aaron Lu Subject: Re: [RFC PATCH v2 1/8] ACPI: Introduce ACPI D3_COLD state support Date: Mon, 12 Mar 2012 10:00:16 +0800 Message-ID: <20120312020016.GB2820@ladygaga> References: <1330592577-16546-1-git-send-email-ming.m.lin@intel.com> <1330592577-16546-2-git-send-email-ming.m.lin@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Return-path: Content-Disposition: inline In-Reply-To: <1330592577-16546-2-git-send-email-ming.m.lin@intel.com> Sender: linux-acpi-owner@vger.kernel.org To: Lin Ming Cc: Zhang Rui , Jeff Garzik , Alan Stern , "Rafael J. Wysocki" , Tejun Heo , linux-kernel@vger.kernel.org, linux-ide@vger.kernel.org, linux-scsi@vger.kernel.org, linux-pm@vger.kernel.org, linux-acpi List-Id: linux-scsi@vger.kernel.org Hi, On Thu, Mar 01, 2012 at 05:02:50PM +0800, Lin Ming wrote: > From: Zhang Rui > > If a device has _PR3, it means the device supports D3_COLD. This confused me...So this means if a device is put to D3, instead of turning up the power resources referenced in _PR3, turning them all off will make the device in D3 cold. This is understandable, but what about _PR0? What power state this device is in when I turned off all the power resources referenced in _PR0? Undefined? I'm also confused with _PS3, what power state the device is in after its _PS3 is executed? The spec said it will be in D3 cold or D3 hot, so I guess there is no way to tell, right? Thanks, Aaron > Add the ability to validate and enter D3_COLD state in ACPI. > > Signed-off-by: Zhang Rui > Signed-off-by: Lin Ming > --- > drivers/acpi/power.c | 4 ++-- > drivers/acpi/scan.c | 7 +++++++ > 2 files changed, 9 insertions(+), 2 deletions(-) > > diff --git a/drivers/acpi/power.c b/drivers/acpi/power.c > index 9ac2a9f..0d681fb 100644 > --- a/drivers/acpi/power.c > +++ b/drivers/acpi/power.c > @@ -500,14 +500,14 @@ int acpi_power_transition(struct acpi_device *device, int state) > { > int result; > > - if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3)) > + if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3_COLD)) > return -EINVAL; > > if (device->power.state == state) > return 0; > > if ((device->power.state < ACPI_STATE_D0) > - || (device->power.state > ACPI_STATE_D3)) > + || (device->power.state > ACPI_STATE_D3_COLD)) > return -ENODEV; > > /* TBD: Resources must be ordered. */ > diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c > index 8ab80ba..571396c 100644 > --- a/drivers/acpi/scan.c > +++ b/drivers/acpi/scan.c > @@ -885,6 +885,13 @@ static int acpi_bus_get_power_flags(struct acpi_device *device) > acpi_bus_add_power_resource(ps->resources.handles[j]); > } > > + /* The exist of _PR3 indicates D3Cold support */ > + if (i == ACPI_STATE_D3) { > + status = acpi_get_handle(device->handle, object_name, &handle); > + if (ACPI_SUCCESS(status)) > + device->power.states[ACPI_STATE_D3_COLD].flags.valid = 1; > + } > + > /* Evaluate "_PSx" to see if we can do explicit sets */ > object_name[2] = 'S'; > status = acpi_get_handle(device->handle, object_name, &handle); > -- > 1.7.2.5 > >