In each case, if the NULL test on qc is needed, then the derefernce
should be after the NULL test.

A simplified version of the semantic match that detects this problem is as
follows (http://coccinelle.lip6.fr/):

// <smpl>
@match exists@
expression x, E;
identifier fld;
@@

* x->fld
  ... when != \(x = E\|&x\)
* x == NULL
// </smpl>
Signed-off-by: NJulia Lawall <julia@diku.dk>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

When an internal command fails, it should be failed directly without
invoking EH.  In the original implemetation, this was accomplished by
letting internal command bypass failure handling in ata_qc_complete().
However, later changes added post-successful-completion handling to
that code path and the success path is no longer adequate as internal
command failure path.  One of the visible problems is that internal
command failure due to timeout or other freeze conditions would
spuriously trigger WARN_ON_ONCE() in the success path.

This patch updates failure path such that internal command failure
handling is contained there.
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: stable@kernel.org
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Add ->gtf_filter to ata_device and set it to ata_acpi_gtf_filter when
initializing ata_link.  This is to allow quirks which apply different
gtf filters.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Commit 54c38444 makes libata abort qcs
after the port is frozen.  This is necessary to guarantee that TF
registers are accessed after the DMA engine is shutdown after an
error.  However, this triggers WARN_ON_ONCE() check in
ata_qc_complete() spuriously.  Move WARN_ON_ONCE() downwards such that
failing commands while frozen doesn't trigger it.
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: stable <stable@kernel.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

ata_tf_read_block() has off-by-one error when converting CHS address
to LBA.  The bug isn't very visible because ata_tf_read_block() is
used only when generating sense data for a failed RW command and CHS
addressing isn't used too often these days.

This problem was spotted by Atsushi Nemoto.
Signed-off-by: NTejun Heo <tj@kernel.org>
Reported-by: NAtsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Hopefully results in fewer on-the-wire FIS's and no breakage.  We'll see!
Signed-off-by: NShaohua Li <shaohua.li@intel.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

OCZ Vertex SSD can't do HPA and not in a usual way.  It reports HPA,
allows unlocking but then fails all IOs which fall in the unlocked
area.  Quirk it so that HPA unlocking is not used for the device.

Reported by Daniel Perup in bnc#522414.

 https://bugzilla.novell.com/show_bug.cgi?id=522414Signed-off-by: NTejun Heo <tj@kernel.org>
Reported-by: NDaniel Perup <probe@spray.se>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

On certain configurations, HPA isn't or can't be unlocked during
probing but it somehow ends up unlocked afterwards.  In the following
thread, the problem can be reliably reproduced after resuming from
STR.  The BIOS turns on HPA during boot but forgets to do it during
resume.

  http://thread.gmane.org/gmane.linux.kernel/858310

This patch updates libata revalidation such that it considers native
n_sectors.  If the device size has increased to match native
n_sectors, it's assumed that HPA has been unlocked involuntarily and
the device is recognized as the same one.  This should be fairly safe
while nicely working around the problem.
Signed-off-by: NTejun Heo <tj@kernel.org>
Reported-by: NChristof Warlich <christof@warlich.name>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

PIONEER DVD-RW DVRTD08 times out SETXFER if no media is present.  The
device is SATA and simply skipping SETXFER works around the problem.
Implement ATA_HORKAGE_NOSETXFER and apply it to the device.

Reported by Moritz Rigler in the following thread.

  http://thread.gmane.org/gmane.linux.ide/36790

and by Lars in bko#9540.

Updated to whine and ignore NOSETXFER if PATA component is detected as
suggested by Alan Cox.
Signed-off-by: NTejun Heo <tj@kernel.org>
Reported-by: NMoritz Rigler <linux-ide@momail.e4ward.com>
Reported-by: NLars <lars21ce@gmx.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Before issuing reset, libata configures xfermode to PIO0 which makes
some drivers turn on IORDY which may cause the controller to lock up
if the port is not occupied.  IORDY isn't necessary at this point
anyway.  Make ata_pio_need_iordy() return zero if it's being called
for reset.

This fixes bko#11703.  Reported and tracked down by Daniel Gnoutcheff
and Constantine Gavrilov.
Signed-off-by: NTejun Heo <tj@kernel.org>
Reported-by: NDaniel Gnoutcheff <gnoutchd@union.edu>
Cc: Constantine Gavrilov <constantine.gavrilov@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

1. add defaults to description where possible
2. add value definition (off=0, on=1) where missing

v2: reformatted as per request by Jeff Garzik <jgarzik@pobox.com>
    "Enable foo (0=off, 1=on [default])"
Signed-off-by: NEvgeni Golov <sargentd@die-welt.net>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

We very rarely (if ever) complete more than one command in the
sactive mask at the time, even for extremely high IO rates. So
looping over the entire range of possible tags is pointless,
instead use __ffs() to just find the completed tags directly.

Updated to clear the tag from the done_mask instead of shifting
done_mask down as suggested by From: Tejun Heo <htejun@gmail.com>
Verified with a user space tester to produce the same results.
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

79b42bab fixed identifying ATA devices
reporting 3c/c3 signature which belongs to SEMB devices now. However,
suspending the machine with such device (WDC WD2500AAJS-6 01.0) fails
with the following:

hda: host max PIO4 wanted PIO255(auto-tune) selected PIO4
hda: UDMA/100 mode selected
hdb: host max PIO4 wanted PIO255(auto-tune) selected PIO4
hdb: UDMA/66 mode selected
sd 1:0:0:0: [sda] Starting disk
ata5: SATA link down (SStatus 0 SControl 300)
ata1: SATA link down (SStatus 0 SControl 300)
ata3: SATA link down (SStatus 0 SControl 300)
ata6: SATA link down (SStatus 0 SControl 300)
ata2: softreset failed (device not ready)
ata2: failed due to HW bug, retry pmp=0
ata4: softreset failed (device not ready)
ata4: failed due to HW bug, retry pmp=0
ata4: SATA link up 3.0 Gbps (SStatus 123 SControl 300)
ata2: SATA link up 3.0 Gbps (SStatus 123 SControl 300)
ata2.00: class mismatch 1 != 7
ata2.00: revalidation failed (errno=-19)
ata2: limiting SATA link speed to 1.5 Gbps
ata4.00: configured for UDMA/133
ata2: softreset failed (device not ready)
ata2: failed due to HW bug, retry pmp=0
ata2: SATA link up 1.5 Gbps (SStatus 113 SControl 310)
ata2.00: class mismatch 1 != 7
ata2.00: revalidation failed (errno=-19)
ata2.00: disabled
sd 1:0:0:0: rejecting I/O to offline device
sd 1:0:0:0: [sda] START_STOP FAILED
sd 1:0:0:0: [sda] Result: hostbyte=0x01 driverbyte=0x00
PM: Device 1:0:0:0 failed to thaw: error 65536
sd 3:0:0:0: [sdb] Starting disk

due to a class mismatch in ata_dev_revalidate(). Fix it by adding the
ATA_DEV_SEMB device class to the check.

CC: Tejun Heo <htejun@gmail.com>
Signed-off-by: NBorislav Petkov <petkovbb@gmail.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Use ATA_ID_CFA_* constants for CFA specific identify data words 162 and 163.
Signed-off-by: NSergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

WDC WD1600JS-62MHB5 successfully hits the window between ATA/ATAPI-7
and Serial ATA II standards and reports 3c/c3 signature which now is
assigned to SEMB.  Make ata_dev_classify() report ATA_DEV_SEMB on the
sig and let ata_dev_read_id() work around it by trying IDENTIFY once.

This fixes bko#11579.
Signed-off-by: NTejun Heo <tj@kernel.org>
Reported-by: NDavid Haun <drhaun88@gmail.com>
Reported-by: NLars Wirzenius <liw@liw.fi>
Reported-by: NJuan Manuel <jmcarranza@gmail.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Also remove the now-useless debug printouts which are supposed to
tell us when the scan starts and ends.
Signed-off-by: NVegard Nossum <vegard.nossum@gmail.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Make libata more robust when parsing the multi_count
field from a drive's identify data.  This prevents us from
attempting to use dubious multi_count values ad infinitum.

Reset dev->multi_count to zero and reprobe it each time
through this routine, as it can change on device reset.

Also ensure that the reported "maximum" value is valid
and is a power of two, and that the reported "count" value
is valid and also a power of two.  And that the "count"
value is not greater than the "maximum" value.
Signed-off-by: NMark Lord <mlord@pobox.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Signed-off-by: NMark Lord <mlord@pobox.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Hanno Böck reported a problem where an old Conner CP30254 240MB hard drive
was reported as 1.1TB in capacity by libata:

http://lkml.org/lkml/2009/2/13/134

This was caused by libata trusting the drive's reported current capacity in
sectors in identify words 57 and 58 if the drive does not support LBA and the
current CHS translation values appear valid. Unfortunately it seems older
ATA specs were vague about what this field should contain and a number of drives
used values with wrong byte order or that were totally bogus. There's no
unique information that it conveys and so we can just calculate the number
of sectors from the reported current CHS values.

While we're at it, clean up this function to use named constants for the
identify word values.
Signed-off-by: NRobert Hancock <hancockrwd@gmail.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

libata passes the returned value of dma_map_sg() to
dma_unmap_sg(),which is the misuse of dma_unmap_sg().

DMA-mapping.txt says:

To unmap a scatterlist, just call:

	pci_unmap_sg(pdev, sglist, nents, direction);

Again, make sure DMA activity has already finished.

PLEASE NOTE:  The 'nents' argument to the pci_unmap_sg call must be
              the _same_ one you passed into the pci_map_sg call,
	      it should _NOT_ be the 'count' value _returned_ from the
              pci_map_sg call.
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Acked-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

3Gbps is often much more prone to transmission failures.  It's usually
okay to let EH handle speed down after transmission failures but some
WD My Book drives completely shutdown after certain transmission
failures and after it only power cycling can revive them.  Combined
with the fact that external drives often end up with cable assembly
which is longer than usual and more likely to have intervening gender,
this makes these drives very likely to shutdown under certain
configurations virtually rendering them unusable.

This patch implements HOARKGE_1_5_GBPS and applies it to WD My Book
such that 1.5Gbps is forced once the device is identified.

Please take a look at the following bz for related reports.

  http://bugzilla.kernel.org/show_bug.cgi?id=9913Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Add @spd_limit to sata_down_spd_limit() so that the caller can specify
the SPD limit it wants.  This parameter doesn't get in the way even
when it's too low.  The closest possible limit is applied.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

dev->ering used to be cleared together with the rest of ata_device in
ata_dev_init() which is called whenever a probing event occurs.
dev->ering is about to be used to track probing failures so it needs
to remain persistent over multiple porbing events.  This patch
achieves this by doing the following.

* Instead of CLEAR_OFFSET, define CLEAR_BEGIN and CLEAR_END and only
  clear between BEGIN and END.  ering is moved after END.  The split
  of persistent area is to allow hotter items remain at the head.

* ering is explicitly cleared on ata_dev_disable() and when device
  attach succeeds.  So, ering is persistent throug a device's life
  time (unless explicitly cleared of course) and also through periods
  inbetween disablement of an attached device and successful detection
  of the next one.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

sata_down_spd_limit() should check whether the link is online before
using the SPD value to determine how to limit the link speed.  Factor
out onlineness test and test it from sata_down_spd_limit().
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

ata_dev_disable() is about to be more tightly integrated into EH
logic.  Move it to libata-eh.c.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Fix libata kernel-doc warnings:

Warning(linux-next-20090120//drivers/ata/libata-core.c:4720): Excess function parameter 'dev' description in 'ata_qc_new'
Warning(linux-next-20090120//drivers/ata/libata-scsi.c:428): No description found for parameter 'ap'
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

The forthcoming OCTEON SOC Compact Flash driver needs an additional
timing value that was not available in the ata_timing table.  I add a
new column for dmack_hold time.  The values were obtained from the
Compact Flash specification Rev 4.1.
Signed-off-by: NDavid Daney <ddaney@caviumnetworks.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

for SAS drivers.

Caught by Ke Wei (and team?) at Marvell.

Also, move the ata_scsi_ioctl export to libata-scsi.c, as that seems to be the
general trend.
Acked-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

In a discussio with Jeff Garzik, he mentioned that the serialization
for the libata port probes only needs to be within the domain of a host.
This means that for the first port of each host (with ID 0), we don't
need to wait, so we can relax our serialization a little.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch adds a per host flag that allows drivers to opt in into
having its busses scanned in parallel.

Drivers that do not set this flag get their ports scanned in
the "original" sequence.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Convert WARN_ON() on command issue/completion paths to WARN_ON_ONCE()
so that libata doesn't spam the machine even when one of those
conditions triggers repeatedly.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

According to the Compact Flash specification r4.1, PIO modes 5 and 6
do not use iordy.
Signed-off-by: NDavid Daney <ddaney@caviumnetworks.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

The present AHCI driver seems to support SATA GEN 3 speed, but the related
messages should be modified.
Signed-off-by: NShane Huang <shane.huang@amd.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

As suggested by Linus: Don't do the libata init in 2 separate
steps with a global sync inbetween, but do it as one async step,
with a local sync before registering the device.

This cuts the boottime on my machine with 2 sata controllers down
significantly, and it seems to work. Would be nice if the libata
folks take a good look at this patch though..
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>

This patch makes the libata port scanning asynchronous (per device).
There is a synchronization point before doing the actual disk scan
so that device ordering is not affected.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>

The patchlet below blacklists NCQ on OCZ CORE v2 SSD drive(s). Even
though the drive advertises NCQ support with queue depth 1, it responds
with all-zeroes FIS to NCQ commands which triggers ata error handling
several times before the kernel decides to disable NCQ on the drive.
Signed-off-by: NLubomir Bulej <lubomir.bulej@dsrg.mff.cuni.cz>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Signed-off-by: NQinghuang Feng <qhfeng.kernel@gmail.com>

ata_port_detach() first made sure EH saw ATA_PFLAG_UNLOADING and then
assumed EH context belongs to it and performed detach operation
itself.  However, UNLOADING doesn't disable all of EH and this could
lead to problems including triggering WARN_ON()'s in EH path.

This patch makes port detach behave more like other EH actions such
that ata_port_detach() requests EH to detach and waits for completion.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

When restoring SControl during detach, PMP links should be handled
first as changing SControl of the host link can affect SCR access of
PMP links.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

There currently are the following looping constructs.

* __ata_port_for_each_link() for all available links
* ata_port_for_each_link() for edge links
* ata_link_for_each_dev() for all devices
* ata_link_for_each_dev_reverse() for all devices in reverse order

Now there's a need for looping construct which is similar to
__ata_port_for_each_link() but iterates over PMP links before the host
link.  Instead of adding another one with long name, do the following
cleanup.

* Implement and export ata_link_next() and ata_dev_next() which take
  @mode parameter and can be used to build custom loop.
* Implement ata_for_each_link() and ata_for_each_dev() which take
  looping mode explicitly.

The following iteration modes are implemented.

* ATA_LITER_EDGE		: loop over edge links
* ATA_LITER_HOST_FIRST		: loop over all links, host link first
* ATA_LITER_PMP_FIRST		: loop over all links, PMP links first

* ATA_DITER_ENABLED		: loop over enabled devices
* ATA_DITER_ENABLED_REVERSE	: loop over enabled devices in reverse order
* ATA_DITER_ALL			: loop over all devices
* ATA_DITER_ALL_REVERSE		: loop over all devices in reverse order

This change removes exlicit device enabledness checks from many loops
and makes it clear which ones are iterated over in which direction.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>