Add new ATA device type for ZAC devices.
Acked-by: NChristoph Hellwig <hch@lst.de>
Acked-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NTejun Heo <tj@kernel.org>

libata-eh.c should handle AMNF error condition (error byte bit 0,
usually code 0x01) in libata-eh.c along with UNC as a media error so
SCSI stack can handle it properly (translation code 0x01 is already
present in libata-scsi.c) but was never passed down due to lack of
handling in EH.

While using linux-based machine (AMD 6550M-based notebook, PCI IDs for the
controller are 1022:7801 subsys 1025:059d) and ddrescue to salvage data
from failing hard drive (WD7500BPVT 2.5" 750G SATA2), I've found that pure
AMNF 0x01 error code generates generic "device error" that is retried
several times by SCSI stack instead of "media error" that is passed up to
software.

So we may assume deprecated AMNF error code is surely not dead yet, and
it's better for it to be handled properly. As we may see it is used by
modern enough devices, and used properly: drive returned AMNF only when IDs
for track cannot be read completely due to dying head or positioning,
otherwise it returned UNC(orrectables).

Not handling it causes wrong generic error code ("device error") reporting
down the stack, can damage failing drives further because of excessive
retries, and slows salvaging down a lot. Also, there is handling code in
libata-scsi.c for 0x01 AMNF error already.

https://bugzilla.kernel.org/show_bug.cgi?id=80031

tj: Shortened $SUBJ and moved its content to the first paragraph.
Signed-off-by: NAlexey Asemov <alex@alex-at.ru>
Signed-off-by: NTejun Heo <tj@kernel.org>

Tejun says:
  "At least for libata, worrying about suspend/resume failures don't make
   whole lot of sense.  If suspend failed, just proceed with suspend.  If
   the device can't be woken up afterwards, that's that.  There isn't
   anything we could have done differently anyway.  The same for resume, if
   spinup fails, the device is dud and the following commands will invoke
   EH actions and will eventually fail.  Again, there really isn't any
   *choice* to make.  Just making sure the errors are handled gracefully
   (ie. don't crash) and the following commands are handled correctly
   should be enough."

The only libata user that actually cares about the result from a suspend
operation is libsas.  However, it only cares about whether queuing a new
operation collides with an in-flight one.  All libsas does with the
error is retry, but we can just let libata wait for the previous
operation before continuing.

Other cleanups include:
1/ Unifying all ata port pm operations on an ata_port_pm_ prefix
2/ Marking all ata port pm helper routines as returning void, only
   ata_port_pm_ entry points need to fake a 0 return value.
3/ Killing ata_port_{suspend|resume}_common() in favor of calling
   ata_port_request_pm() directly
4/ Killing the wrappers that just do a to_ata_port() conversion
5/ Clearly marking the entry points that do async operations with an
  _async suffix.

Reference: http://marc.info/?l=linux-scsi&m=138995409532286&w=2

Cc: Phillip Susi <psusi@ubuntu.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Suggested-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NTodd Brandt <todd.e.brandt@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

Prompted by the social effort in the US to discourage usage of the
adjective "retarded".

In this case we needlessly anthropomorphize hard drives.  The
implication is that due to design deficiencies in the device reset
recovery time is negatively impacted.  We can simply clearly state that
fact.  "Exceptional devices cause outliers in reset recovery time." This
steers clear of any unintended comparison of such devices to humans with
cognitive disabilities.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

Remove an unnecessary arithmetic operation from a call to snprintf, because
the size parameter of snprintf includes the trailing null space.
Also, initialize the buffer on definition instead of a memset call.
Signed-off-by: NLevente Kurusa <levex@linux.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

Use this new function to make code more comprehensible, since we are
reinitialzing the completion, not initializing.

[akpm@linux-foundation.org: linux-next resyncs]
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Acked-by: Linus Walleij <linus.walleij@linaro.org> (personally at LCE13)
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add some missing command enumerations from the ATA-8 ACS-3 spec into
include/linux/ata.h, and add the corresponding human-readable command
descriptions in libata-eh.c.
Signed-off-by: NRobert Hancock <hancockrwd@gmail.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

libata EH decrements scmd->retries when the command failed for reasons
unrelated to the command itself so that, for example, commands aborted
due to suspend / resume cycle don't get penalized; however,
decrementing scmd->retries isn't enough for ATA passthrough commands.

Without this fix, ATA passthrough commands are not resend to the
drive, and no error is signalled to the caller because:

- allowed retry count is 1
- ata_eh_qc_complete fill the sense data, so result is valid
- sense data is filled with untouched ATA registers.
Signed-off-by: NGwendal Grignou <gwendal@google.com>
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org

Jeff moved on to a greener pasture.

 s/Maintained by: Jeff Garzik/Maintained by: Tejun Heo/g
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: Jeff Garzik <jgarzik@pobox.com>

We need to do different things for system PM and runtime PM, e.g. we do
not need to enable runtime wake for ZPODD when we are doing system
suspend, etc.

Currently, we use PMSG_SUSPEND for both system suspend and runtime
suspend and PMSG_ON for both system resume and runtime resume. Change
this by using PMSG_AUTO_SUSPEND for runtime suspend and PMSG_AUTO_RESUME
for runtime resume. And since PMSG_ON means no transition, it is changed
to PMSG_RESUME for ata port's system resume.

The ata_acpi_set_state is modified accordingly, and the sata case and
pata case is seperated for easy reading.
Signed-off-by: NAaron Lu <aaron.lu@intel.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

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: NAaron Lu <aaron.lu@intel.com>
Acked-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

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: NAaron Lu <aaron.lu@intel.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

It should be a mistake introduced by commit 8d899e70.

qc->flags can't be set AC_ERR_*
Signed-off-by: NBian Yu <bianyu@kedacom.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

ata_device->dma_mode's initial value is zero, which is not a valid dma
mode, but ata_dma_enabled will return true for this value. This patch
sets dma_mode to 0xff in reset function, so that ata_dma_enabled will
not return true for this case, or it will cause problem for pata_acpi.

The corrsponding bugzilla page is at:
https://bugzilla.kernel.org/show_bug.cgi?id=49151Reported-by: NPhillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: NAaron Lu <aaron.lu@intel.com>
Tested-by: NSzymon Janc <szymon@janc.net.pl>
Tested-by: NDutra Julio <dutra.julio@gmail.com>
Acked-by: NAlan Cox <alan@linux.intel.com>
Cc: <stable@kernel.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

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: NShane Huang <shane.huang@amd.com>
Reviewed-by: NAaron Lu <aaron.lwe@gmail.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Hotplug testing with libsas currently encounters a 55 second wait for
link recovery to give up.  In the case where the user trusts the
response time of their devices permit the recovery attempts to be
limited to one.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Acked-by: NJeff Garzik <jgarzik@redhat.com>
Acked-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

The function ata_ering_clear_cb is only referenced in this file and
should be marked static to prevent it from being exposed globally.

This quiets the sparse warning:

warning: symbol 'ata_ering_clear_cb' was not declared. Should it be static?
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

When managing shost->host_eh_scheduled libata assumes that there is a
1:1 shost-to-ata_port relationship.  libsas creates a 1:N relationship
so it needs to manage host_eh_scheduled cumulatively at the host level.
The sched_eh and end_eh port port ops allow libsas to track when domain
devices enter/leave the "eh-pending" state under ha->lock (previously
named ha->state_lock, but it is no longer just a lock for ha->state
changes).

Since host_eh_scheduled indicates eh without backing commands pinning
the device it can be deallocated at any time.  Move the taking of the
domain_device reference under the port_lock to guarantee that the
ata_port stays around for the duration of eh.
Reviewed-by: NJacek Danecki <jacek.danecki@intel.com>
Acked-by: NJeff Garzik <jgarzik@redhat.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

ATA and SATA drives have had built-in retries for media errors
for as long as they've been commonplace in computers (early 1990s).

When libata stumbles across a bad sector, it can waste minutes
sitting there doing retry after retry before finally giving up
and letting the higher layers deal with it.

This patch removes retries for media errors only.
Signed-off-by: NMark Lord <mlord@pobox.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Commit d9027470("[libata] Add ATA transport class") introduced
ATA_EFLAG_OLD_ER to mark entries in the error ring as cleared.

But ata_count_probe_trials_cb() didn't check this flag and it still
counts the old error history. So wrong probe trials count is returned
and it causes problem, for example, SATA link speed is slowed down from
3.0Gbps to 1.5Gbps.

Fix it by checking ATA_EFLAG_OLD_ER in ata_count_probe_trials_cb().

Cc: stable <stable@vger.kernel.org> # 2.6.37+
Signed-off-by: NLin Ming <ming.m.lin@intel.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Link resets leave ata affiliations intact, so arrange for libsas to make
an effort to avoid dropping the device due to a slow-to-recover link.
Towards this end carry out reset in the host workqueue so that it can
check for ata devices and kick the reset request to libata.  Hard
resets, in contrast, bypass libata since they are meant for associating
an ata device with another initiator in the domain (tears down
affiliations).

Need to add a new transport_sas_phy_reset() since the current
sas_phy_reset() is a utility function to libsas lldds.  They are not
prepared for it to loop back into eh.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Reenable sending SRST to devices connected behind a Sil3726 PMP.
This allow staggered spinups and handles drives that spins up slowly.

While the drives spin up, the PMP will not accept SRST.
Most controller reissues the reset until the drive is ready, while
some [Sil3124] returns an error.
In ata_eh_error, wait 10s before reset the ATA port and try again.
Signed-off-by: NGwendal Grignou <gwendal@google.com>
Acked-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

They were getting this implicitly by an include of module.h
from device.h -- but we are going to clean that up and break
that include chain, so include export.h explicitly now.
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

... since it does not use it.
Signed-off-by: NSergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

libata EH intentionally left a port frozen if it failed
ata_eh_reset().  The intention was avoiding continuous loop of resets
when the controller or attached device is flaky and reporting spurious
hotplug events.  Once port enters this state, it can be recovered with
manual rescan, which seemed reasonable.

However, outside of my convoluted test setup, there have been very few
reports justifying this choice while there have been more cases where
the automatic freezing of the port after hotplug attempt of a faulty
device caused confusion and led to unnecessary resets.

This patch changes the behavior so that the port is thawed after reset
failure.  This change doesn't necessarily solve but makes it easier
and more intuitive to work around hotplug related problems
(ie. re-pluggin or power cycling the device) as reported in the
followings.

  https://bugzilla.kernel.org/show_bug.cgi?id=34712
  http://thread.gmane.org/gmane.linux.kernel/1123265/focus=49548Signed-off-by: NTejun Heo <tj@kernel.org>
Reported-by: NReartes Guillermo <rtguille@gmail.com>
Reported-by: NBruce Stenning <b.stenning@indigovision.com>
Signed-off-by: NJeff Garzik <jgarzik@pobox.com>

Saves text by removing nearly duplicated text format strings by
creating ata_<foo>_printk functions and printf extension %pV.

ata defconfig size shrinks ~5% (~8KB), allyesconfig ~2.5% (~13KB)

Format string duplication comes from:

 #define ata_link_printk(link, lv, fmt, args...) do { \
       if (sata_pmp_attached((link)->ap) || (link)->ap->slave_link)    \
               printk("%sata%u.%02u: "fmt, lv, (link)->ap->print_id,   \
                      (link)->pmp , ##args); \
       else \
               printk("%sata%u: "fmt, lv, (link)->ap->print_id , ##args); \
       } while(0)

Coalesce long formats.

$ size drivers/ata/built-in.*
   text	   data	    bss	    dec	    hex	filename
 544969	  73893	 116584	 735446	  b38d6	drivers/ata/built-in.allyesconfig.ata.o
 558429	  73893	 117864	 750186	  b726a	drivers/ata/built-in.allyesconfig.dev_level.o
 141328	  14689	   4220	 160237	  271ed	drivers/ata/built-in.defconfig.ata.o
 149567	  14689	   4220	 168476	  2921c	drivers/ata/built-in.defconfig.dev_level.o
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NJeff Garzik <jgarzik@pobox.com>

To work around controllers which can't properly plug events while
reset, ata_eh_reset() clears error states and ATA_PFLAG_EH_PENDING
after reset but before RESET is marked done.  As reset is the final
recovery action and full verification of devices including onlineness
and classfication match is done afterwards, this shouldn't lead to
lost devices or missed hotplug events.

Unfortunately, it forgot to thaw the port when clearing EH_PENDING, so
if the condition happens after resetting an empty port, the port could
be left frozen and EH will end without thawing it, making the port
unresponsive to further hotplug events.

Thaw if the port is frozen after clearing EH_PENDING.  This problem is
reported by Bruce Stenning in the following thread.

 http://thread.gmane.org/gmane.linux.kernel/1123265

stable: I think we should weather this patch a bit longer in -rcX
	before sending it to -stable.  Please wait at least a month
	after this patch makes upstream.  Thanks.

-v2: Fixed spelling in the comment per Dave Howorth.
Signed-off-by: NTejun Heo <tj@kernel.org>
Reported-by: NBruce Stenning <b.stenning@indigovision.com>
Cc: stable@kernel.org
Cc: Dave Howorth <dhoworth@mrc-lmb.cam.ac.uk>
Signed-off-by: NJeff Garzik <jgarzik@pobox.com>

Give users the option of completely powering off unoccupied
SATA ports using the existing min_power link_power_management_policy
option.  When the use selects this option on an empty port, we
will power the port off by setting DET to off.  For occupied ports,
behavior is unchanged.
Signed-off-by: NKristen Carlson Accardi <kristen@linux.intel.com>
Signed-off-by: NJeff Garzik <jgarzik@pobox.com>

ae01b249 (libata: Implement ATA_FLAG_NO_DIPM and apply it to mcp65)
added ATA_FLAG_NO_DIPM and made ata_eh_set_lpm() check the flag.
However, @ap is NULL if @link points to a PMP link and thus the
unconditional @ap->flags dereference leads to the following oops.

  BUG: unable to handle kernel NULL pointer dereference at 0000000000000018
  IP: [<ffffffff813f98e1>] ata_eh_recover+0x9a1/0x1510
  ...
  Pid: 295, comm: scsi_eh_4 Tainted: P            2.6.38.5-core2 #1 System76, Inc. Serval Professional/Serval Professional
  RIP: 0010:[<ffffffff813f98e1>]  [<ffffffff813f98e1>] ata_eh_recover+0x9a1/0x1510
  RSP: 0018:ffff880132defbf0  EFLAGS: 00010246
  RAX: 0000000000000000 RBX: ffff880132f40000 RCX: 0000000000000000
  RDX: ffff88013377c000 RSI: ffff880132f40000 RDI: 0000000000000000
  RBP: ffff880132defce0 R08: ffff88013377dc58 R09: ffff880132defd98
  R10: 0000000000000000 R11: 00000000ffffffff R12: 0000000000000000
  R13: 0000000000000000 R14: ffff88013377c000 R15: 0000000000000000
  FS:  0000000000000000(0000) GS:ffff8800bf700000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
  CR2: 0000000000000018 CR3: 0000000001a03000 CR4: 00000000000406e0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
  Process scsi_eh_4 (pid: 295, threadinfo ffff880132dee000, task ffff880133b416c0)
  Stack:
   0000000000000000 ffff880132defcc0 0000000000000000 ffff880132f42738
   ffffffff813ee8f0 ffffffff813eefe0 ffff880132defd98 ffff88013377f190
   ffffffffa00b3e30 ffffffff813ef030 0000000032defc60 ffff880100000000
  Call Trace:
   [<ffffffff81400867>] sata_pmp_error_handler+0x607/0xc30
   [<ffffffffa00b273f>] ahci_error_handler+0x1f/0x70 [libahci]
   [<ffffffff813faade>] ata_scsi_error+0x5be/0x900
   [<ffffffff813cf724>] scsi_error_handler+0x124/0x650
   [<ffffffff810834b6>] kthread+0x96/0xa0
   [<ffffffff8100cd64>] kernel_thread_helper+0x4/0x10
  Code: 8b 95 70 ff ff ff b8 00 00 00 00 48 3b 9a 10 2e 00 00 48 0f 44 c2 48 89 85 70 ff ff ff 48 8b 8d 70 ff ff ff f6 83 69 02 00 00 01 <48> 8b 41 18 0f 85 48 01 00 00 48 85 c9 74 12 48 8b 51 08 48 83
  RIP  [<ffffffff813f98e1>] ata_eh_recover+0x9a1/0x1510
   RSP <ffff880132defbf0>
  CR2: 0000000000000018

Fix it by testing @link->ap->flags instead.

stable: ATA_FLAG_NO_DIPM was added during 2.6.39 cycle but was
        backported to 2.6.37 and 38.  This is a fix for that and thus
        also applicable to 2.6.37 and 38.
Signed-off-by: NTejun Heo <tj@kernel.org>
Reported-by: N"Nathan A. Mourey II" <nmoureyii@ne.rr.com>
LKML-Reference: <1304555277.2059.2.camel@localhost.localdomain>
Cc: Connor H <cmdkhh@gmail.com>
Cc: stable@kernel.org
Signed-off-by: NJeff Garzik <jgarzik@pobox.com>

NVIDIA mcp65 familiy of controllers cause command timeouts when DIPM
is used.  Implement ATA_FLAG_NO_DIPM and apply it.

This problem was reported by Stefan Bader in the following thread.

 http://thread.gmane.org/gmane.linux.ide/48841

stable: applicable to 2.6.37 and 38.
Signed-off-by: NTejun Heo <tj@kernel.org>
Reported-by: NStefan Bader <stefan.bader@canonical.com>
Cc: stable@kernel.org
Signed-off-by: NJeff Garzik <jgarzik@pobox.com>

Fixes generated by 'codespell' and manually reviewed.
Signed-off-by: NLucas De Marchi <lucas.demarchi@profusion.mobi>

Right at the moment, the libata error handler is incredibly
monolithic.  This makes it impossible to use from composite drivers
like libsas and ipr which have to handle error themselves in the first
instance.

The essence of the change is to split the monolithic error handler
into two components: one which handles a queue of ata commands for
processing and the other which handles the back end of readying a
port.  This allows the upper error handler fine grained control in
calling libsas functions (and making sure they only get called for ATA
commands whose lower errors have been fixed up).
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

The SCSI host eh_cmd_q should be protected by the host lock (not the
port lock).  This probably doesn't matter that much at the moment,
since we try to serialise the add and eh pieces, but it might matter
in future for more convenient error handling.  Plus this switches
libata to the standard eh pattern where you lock, remove from the cmd
queue to a local list and unlock and then operate on the local list.
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

ata_eh_analyze_serror() suppresses hotplug notifications if LPM is
being used because LPM generates spurious hotplug events.  It compared
whether link->lpm_policy was different from ATA_LPM_MAX_POWER to
determine whether LPM is enabled; however, this is incorrect as for
drivers which don't implement LPM, lpm_policy is always
ATA_LPM_UNKNOWN.  This disabled hotplug detection for all drivers
which don't implement LPM.

Fix it by comparing whether lpm_policy is greater than
ATA_LPM_MAX_POWER.
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: stable@kernel.org
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Right at the moment, the libata error handler is incredibly
monolithic.  This makes it impossible to use from composite drivers
like libsas and ipr which have to handle error themselves in the first
instance.

The essence of the change is to split the monolithic error handler
into two components: one which handles a queue of ata commands for
processing and the other which handles the back end of readying a
port.  This allows the upper error handler fine grained control in
calling libsas functions (and making sure they only get called for ATA
commands whose lower errors have been fixed up).

Cc: Tejun Heo <tj@kernel.org>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

The SCSI host eh_cmd_q should be protected by the host lock (not the
port lock).  This probably doesn't matter that much at the moment,
since we try to serialise the add and eh pieces, but it might matter
in future for more convenient error handling.  Plus this switches
libata to the standard eh pattern where you lock, remove from the cmd
queue to a local list and unlock and then operate on the local list.

Cc: Tejun Heo <tj@kernel.org>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

Low level drivers may behave differently depending on the current
link->lpm_policy.  During ata_eh_set_lpm(), DIPM enable commands are
issued after the successful completion of ap->ops->set_lpm(), which
means that the controller is already in the target state.  This causes
DIPM enable commands to be processed with mismatching controller power
state and link->lpm_policy value.

In ahci, link->lpm_policy is used to ignore certain PHY events if LPM
is enabled; however, as DIPM commands are issued with stale
link->lpm_policy, they sometimes end up triggering these conditions
and get aborted leading to LPM configuration failure.

Fix it by updating link->lpm_policy before issuing DIPM enable
commands.
Signed-off-by: NTejun Heo <tj@kernel.org>
Reported-by: NKyle McMartin <kyle@mcmartin.ca>
Cc: stable@kernel.org
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

In libata, the non-EH code paths should always take and release
ap->lock explicitly when accessing hardware or shared data structures.
However, once EH is active, it's assumed that the port is owned by EH
and EH methods don't explicitly take ap->lock unless race from irq
handler or other code paths are expected.  However, libata EH didn't
guarantee exclusion among EHs for ports of the same host.  IOW,
multiple EHs may execute in parallel on multiple ports of the same
controller.

In many cases, especially in SATA, the ports are completely
independent of each other and this doesn't cause problems; however,
there are cases where different ports share the same resource, which
lead to obscure timing related bugs such as the one fixed by commit
213373cf (ata_piix: fix locking around SIDPR access).

This patch implements exclusion among EHs of the same host.  When EH
begins, it acquires per-host EH ownership by calling ata_eh_acquire().
When EH finishes, the ownership is released by calling
ata_eh_release().  EH ownership is also released whenever the EH
thread goes to sleep from ata_msleep() or explicitly and reacquired
after waking up.

This ensures that while EH is actively accessing the hardware, it has
exclusive access to it while allowing EHs to interleave and progress
in parallel as they hit waiting stages, which dominate the time spent
in EH.  This achieves cross-port EH exclusion without pervasive and
fragile changes while still allowing parallel EH for the most part.

This was first reported by yuanding02@gmail.com more than three years
ago in the following bugzilla.  :-)

  https://bugzilla.kernel.org/show_bug.cgi?id=8223Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Reported-by: yuanding02@gmail.com
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Add optional @ap argument to ata_wait_register() and replace msleep()
calls with ata_msleep() which take optional @ap in addition to the
duration.  These will be used to implement EH exclusion.

This patch doesn't cause any behavior difference.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Port multipliers can do DIPM on fan-out links fine.  Implement support
for it.  Tested w/ SIMG 57xx and marvell PMPs.  Both the host and
fan-out links enter power save modes nicely.

SIMG 37xx and 47xx report link offline on SStatus causing EH to detach
the devices.  Blacklisted.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>