linux-toradex.git/drivers/ata/libata.h, branch v3.14.3

ATA / ACPI: remove power dependent device handling

2013-10-17T13:38:53+00:00

Previously, we wanted SCSI devices corrsponding to ATA devices to
be runtime resumed when the power resource for those ATA device was
turned on by some other device, so we added the SCSI device to the
dependent device list of the ATA device's ACPI node.  However, this
code has no effect after commit 41863fc (ACPI / power: Drop automaitc
resume of power resource dependent devices) and the mechanism it was
supposed to implement is regarded as a bad idea now, so drop it.

[rjw: Changelog]
Signed-off-by: Aaron Lu 
Signed-off-by: Rafael J. Wysocki

libata: acpi: Remove ata_dev_acpi_handle stub in libata.h

2013-08-27T18:07:12+00:00

The ata_dev_acpi_handle is defined in libata-acpi.c and the only
external user is libata-zpodd.c, which is built when CONFIG_ATA_ACPI
is set, so there is no need to make an empty stub function for
ONFIG_ATA_ACPI case in libata.h. It also causes compile errors due to
acpi_handle is not defined when !CONFIG_ACPI. This patch fixes this
problem by removing the empty stub.

Reported-by: Stephen Rothwell 
Signed-off-by: Aaron Lu 
Signed-off-by: Tejun Heo

ata: acpi: rework the ata acpi bind support

2013-08-23T16:09:23+00:00

Binding ACPI handle to SCSI device has several drawbacks, namely:
1 During ATA device initialization time, ACPI handle will be needed
  while SCSI devices are not created yet. So each time ACPI handle is
  needed, instead of retrieving the handle by ACPI_HANDLE macro,
  a namespace scan is performed to find the handle for the corresponding
  ATA device. This is inefficient, and also expose a restriction on
  calling path not holding any lock.
2 The binding to SCSI device tree makes code complex, while at the same
  time doesn't bring us any benefit. All ACPI handlings are still done
  in ATA module, not in SCSI.

Rework the ATA ACPI binding code to bind ACPI handle to ATA transport
devices(ATA port and ATA device). The binding needs to be done only once,
since the ATA transport devices do not go away with hotplug. And due to
this, the flush_work call in hotplug handler for ATA bay is no longer
needed.

Tested on an Intel test platform for binding and runtime power off for
ODD(ZPODD) and hard disk; on an ASUS S400C for binding and normal boot
and S3, where its SATA port node has _SDD and _GTF control methods when
configured as an AHCI controller and its PATA device node has _GTF
control method when configured as an IDE controller. SATA PMP binding
and ATA hotplug is not tested.

Signed-off-by: Aaron Lu 
Tested-by: Dirk Griesbach 
Signed-off-by: Tejun Heo

libata: acpi: remove dead code for ata_acpi_(un)bind

2013-07-25T14:49:13+00:00

Commit 7381fe737 "libata-acpi: remove redundent code for power resource
handling" removed ata_acpi_(un)bind but left their prototypes in libata.h,
so remove them.

Signed-off-by: Aaron Lu 
Signed-off-by: Tejun Heo

libata-acpi: add back ACPI based hotplug functionality

2013-06-24T22:51:33+00:00

Commit 30dcf76acc69 "libata: migrate ACPI code over to new bindings"
mistakenly dropped the code to register hotplug notificaion handler
for ATA port/devices, causing regression for people using ATA bay,
as kernel bug #59871 shows.

Fix this by adding back the hotplug notification handler registration
code.  Since this code has to be run once and notification needs to
be installed on every ATA port/devices handle no matter if there is
actual device attached, we can't do this in binding time for ATA
device ACPI handle, as the binding only occurs when a SCSI device is
created, i.e. there is device attached.  So introduce the
ata_acpi_hotplug_init() function to loop scan all ATA ACPI handles
and if it is available, install the notificaion handler for it during
ATA init time.

With the ATA ACPI handle binding to SCSI device tree, it is possible
now that when the SCSI hotplug work removes the SCSI device, the ACPI
unbind function will find that the corresponding ACPI device has
already been deleted by dock driver, causing a scaring message like:
[  128.263966] scsi 4:0:0:0: Oops, 'acpi_handle' corrupt
Fix this by waiting for SCSI hotplug task finish in our notificaion
handler, so that the removal of ACPI device done in ACPI unbind
function triggered by the removal of SCSI device is run earlier when
ACPI device is still available.

[rjw: Rebased]
References: https://bugzilla.kernel.org/show_bug.cgi?id=59871
Reported-bisected-and-tested-by: Dirk Griesbach 
Signed-off-by: Aaron Lu 
Acked-by: Tejun Heo 
Cc: 3.6+ 
Signed-off-by: Rafael J. Wysocki

libata: handle power transition of ODD

2013-01-21T20:41:56+00:00

When ata port is runtime suspended, it will check if the ODD attched to
it is a zero power(ZP) capable ODD and if the ZP capable ODD is in zero
power ready state. And if this is not the case, the highest acpi state
will be limited to ACPI_STATE_D3_HOT to avoid powering off the ODD. And
if the ODD can be powered off, runtime wake capability needs to be
enabled and powered_off flag will be set to let resume code knows that
the ODD was in powered off state.

And on resume, before it is powered on, if it was powered off during
suspend, runtime wake capability needs to be disabled. After it is
recovered, the ODD is considered functional, post power on processing
like eject tray if the ODD is drawer type is done, and several ZPODD
related fields will also be reset.

Signed-off-by: Aaron Lu 
Acked-by: Tejun Heo 
Signed-off-by: Jeff Garzik

libata: check zero power ready status for ZPODD

2013-01-21T20:41:34+00:00

Per the Mount Fuji spec, the ODD is considered zero power ready when:
  - For slot type ODD, no media inside;
  - For tray type ODD, no media inside and tray closed.

The information can be retrieved by either the returned information of
command GET_EVENT_STATUS_NOTIFICATION(the command is used to poll for
media event) or sense code.

The information provided by the media status byte is not accurate, it
is possible that after a new disc is just inserted, the status byte
still returns media not present. So this information can not be used as
the deciding factor, we use sense code to decide if zpready status is
true.

When we first sensed the ODD in the zero power ready state, the
zp_sampled will be set and timestamp will be recoreded. And after ODD
stayed in this state for some pre-defined period, the ODD is considered
as power off ready and the zp_ready flag will be set. The zp_ready flag
serves as the deciding factor other code will use to see if power off is
OK for the ODD.

The Mount Fuji spec suggests a delay should be used here, to avoid the
case user ejects the ODD and then instantly inserts a new one again, so
that we can avoid a power transition. And some ODDs may be slow to place
its head to the home position after disc is ejected, so a delay here is
generally a good idea. And the delay time can be changed via the module
param zpodd_poweroff_delay.

The zero power ready status check is performed in the ata port's runtime
suspend code path, when port is not frozen yet, as we need to issue some
IOs to the ODD.

Signed-off-by: Aaron Lu 
Signed-off-by: Jeff Garzik

libata: identify and init ZPODD devices

2013-01-21T20:40:35+00:00

The ODD can be enabled for ZPODD if the following three conditions are
satisfied:
1 The ODD supports device attention;
2 The platform can runtime power off the ODD through ACPI;
3 The ODD is either slot type or drawer type.
For such ODDs, zpodd_init is called and a new structure is allocated for
it to store ZPODD related stuffs.

And the zpodd_dev_enabled function is used to test if ZPODD is currently
enabled for this ODD.

A new config CONFIG_SATA_ZPODD is added to selectively build ZPODD code.

Signed-off-by: Aaron Lu 
Acked-by: Tejun Heo 
Signed-off-by: Jeff Garzik

ahci: implement aggressive SATA device sleep support

2012-09-13T05:08:53+00:00

Device Sleep is a feature as described in AHCI 1.3.1 Technical Proposal.
This feature enables an HBA and SATA storage device to enter the DevSleep
interface state, enabling lower power SATA-based systems.

Aggressive Device Sleep enables the HBA to assert the DEVSLP signal as
soon as there are no commands outstanding to the device and the port
specific Device Sleep idle timer has expired. This enables autonomous
entry into the DevSleep interface state without waiting for software
in power sensitive systems.

This patch enables Aggressive Device Sleep only if both host controller
and device support it.

Tested on AMD reference board together with Device Sleep supported device
sample.

Signed-off-by: Shane Huang 
Reviewed-by: Aaron Lu 
Signed-off-by: Jeff Garzik

libata-acpi: add missing inlines in libata.h

2012-07-25T18:15:03+00:00

Adds inline for ata_acpi_unregister/ata_acpi_bind/ata_acpi_unbind
in drivers/ata/libata.h for !CONFIG_ATA_ACPI to fix below warnings.

warning: 'ata_acpi_unregister' defined but not used [-Wunused-function]
warning: 'ata_acpi_bind' defined but not used [-Wunused-function]
warning: 'ata_acpi_unbind' defined but not used [-Wunused-function]

Reported-by: Stephen Rothwell 
Signed-off-by: Lin Ming 
Signed-off-by: Jeff Garzik