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: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
79b42babba 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: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Use ATA_ID_CFA_* constants for CFA specific identify data words 162 and 163.
Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Jeff 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: Tejun Heo <tj@kernel.org>
Reported-by: David Haun <drhaun88@gmail.com>
Reported-by: Lars Wirzenius <liw@liw.fi>
Reported-by: Juan Manuel <jmcarranza@gmail.com>
Signed-off-by: Jeff 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: Vegard Nossum <vegard.nossum@gmail.com>
Signed-off-by: Jeff 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: Mark Lord <mlord@pobox.com>
Signed-off-by: Jeff 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: Robert Hancock <hancockrwd@gmail.com>
Signed-off-by: Jeff 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: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff 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=9913
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff 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: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff 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: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff 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: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff 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: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff 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: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Jeff 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: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Jeff 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: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Jeff 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: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Linus 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: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Linus 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: Tejun Heo <tj@kernel.org>
Signed-off-by: Linus 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: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Jeff 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: Shane Huang <shane.huang@amd.com>
Signed-off-by: Jeff 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: Arjan 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: Arjan 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: Lubomir Bulej <lubomir.bulej@dsrg.mff.cuni.cz>
Signed-off-by: Jeff Garzik <jgarzik@redhat.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: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff 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: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff 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: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Due to miscommunication, P/N was mistaken as firmware revision
strings. Update it.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Some recent Seagate harddrives have firmware bug which causes FLUSH
CACHE to timeout under certain circumstances if NCQ is being used.
This can be worked around by disabling NCQ and fixed by updating the
firmware. Implement ATA_HORKAGE_FIRMWARE_UPDATE and blacklist these
devices.
The wiki page has been updated to contain information on this issue.
http://ata.wiki.kernel.org/index.php/Known_issues
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Phillip O'Donnell <phillip.odonnell@gmail.com> pointed out that the same
sign extension bug that was fixed in commit ba14a9c2 ("libata: Avoid
overflow in ata_tf_to_lba48() when tf->hba_lbal > 127") also appears to
exist in ata_tf_read_block(). Fix this by adding a cast to u64.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
This patch reverts the following three commits which convert libata to
use block layer tagging.
43a49cbdf3e013e13bf62fca5ccf97
Although using block layer tagging is the right direction, due to the
tight coupling among tag number, data structure allocation and
hardware command slot allocation, libata doesn't work correctly with
the current conversion.
The biggest problem is guaranteeing that tag 0 is always used for
non-NCQ commands. Due to the way blk-tag is implemented and how SCSI
starts and finishes requests, such guarantee can't be made. I'm not
sure whether this would actually break any low level driver but it
doesn't look like a good idea to break such assumption given the
frailty of ATA controllers.
So, for the time being, keep using the old dumb in-libata qc
allocation.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axobe <jens.axboe@oracle.com>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
libata restores SControl on detach; however, trying to restore
non-zero DET can cause undeterministic behavior including PMP device
going offline till power cycling. Mask off DET when restoring
SControl.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
libata always uses PIO for ATAPI commands when the number of bytes to
transfer isn't multiple of 16 but quantum DAT72 chokes on odd bytes
PIO transfers. Implement a horkage to skip the mod16 check and apply
it to the quantum device.
This is reported by John Clark in the following thread.
http://thread.gmane.org/gmane.linux.ide/34748
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: John Clark <clarkjc@runbox.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
libata currently imposes a UDMA5 max transfer rate and 200 sector max
transfer size for SATA devices that sit behind a pata-sata bridge. Lots
of devices have known good bridges that don't need this limit applied.
The MTRON SSD disks are such devices. Transfer rates are increased by
20-30% with the restriction removed.
So add a "blacklist" entry for the MTRON devices, with a flag indicating
that the bridge is known good.
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
In ata_tf_to_lba48(), when evaluating
(tf->hob_lbal & 0xff) << 24
the expression is promoted to signed int (since int can hold all values
of u8). However, if hob_lbal is 128 or more, then it is treated as a
negative signed value and sign-extended when promoted to u64 to | into
sectors, which leads to the MSB 32 bits of section getting set
incorrectly.
For example, Phillip O'Donnell <phillip.odonnell@gmail.com> reported
that a 1.5GB drive caused:
ata3.00: HPA detected: current 2930277168, native 18446744072344861488
where 2930277168 == 0xAEA87B30 and 18446744072344861488 == 0xffffffffaea87b30
which shows the problem when hob_lbal is 0xae.
Fix this by adding a cast to u64, just as is used by for hob_lbah and
hob_lbam in the function.
Reported-by: Phillip O'Donnell <phillip.odonnell@gmail.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Remove excess kernel-doc function parameter notation from drivers/ata/:
Warning(drivers/ata/libata-core.c:1622): Excess function parameter or struct member 'fn' description in 'ata_pio_queue_task'
Warning(drivers/ata/libata-core.c:4655): Excess function parameter or struct member 'err_mask' description in 'ata_qc_complete'
Warning(drivers/ata/ata_piix.c:751): Excess function parameter or struct member 'udma' description in 'do_pata_set_dmamode'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Fix libata missing kernel-doc:
Warning(lin2628-rc2//drivers/ata/libata-core.c:4562): No description
found for parameter 'tag'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
There were several places where only enabled devices should be
iterated over but device enabledness wasn't checked.
* IDENTIFY data 40 wire check in cable_is_40wire()
* xfer_mode/ncq_enabled saving in ata_scsi_error()
* DUBIOUS_XFER handling in ata_set_mode()
While at it, reformat comments in cable_is_40wire().
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
libata currently has a pretty dumb ATA_MAX_QUEUE loop for finding
a free tag to use. Instead of fixing that up, convert libata to
using block layer tagging - gets rid of code in libata, and is also
much faster.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ap->port_task was not initialized if !CONFIG_ATA_SFF later triggering
lockdep warning. Make sure it's initialized.
Reported by Larry Finger.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
On user request (through sysfs), the IDLE IMMEDIATE command with UNLOAD
FEATURE as specified in ATA-7 is issued to the device and processing of
the request queue is stopped thereafter until the specified timeout
expires or user space asks to resume normal operation. This is supposed
to prevent the heads of a hard drive from accidentally crashing onto the
platter when a heavy shock is anticipated (like a falling laptop
expected to hit the floor). In fact, the whole port stops processing
commands until the timeout has expired in order to avoid any resets due
to failed commands on another device.
Signed-off-by: Elias Oltmanns <eo@nebensachen.de>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Explanation taken from the comment of ata_slave_link_init().
In libata, a port contains links and a link contains devices. There
is single host link but if a PMP is attached to it, there can be
multiple fan-out links. On SATA, there's usually a single device
connected to a link but PATA and SATA controllers emulating TF based
interface can have two - master and slave.
However, there are a few controllers which don't fit into this
abstraction too well - SATA controllers which emulate TF interface
with both master and slave devices but also have separate SCR
register sets for each device. These controllers need separate links
for physical link handling (e.g. onlineness, link speed) but should
be treated like a traditional M/S controller for everything else
(e.g. command issue, softreset).
slave_link is libata's way of handling this class of controllers
without impacting core layer too much. For anything other than
physical link handling, the default host link is used for both master
and slave. For physical link handling, separate @ap->slave_link is
used. All dirty details are implemented inside libata core layer.
From LLD's POV, the only difference is that prereset, hardreset and
postreset are called once more for the slave link, so the reset
sequence looks like the following.
prereset(M) -> prereset(S) -> hardreset(M) -> hardreset(S) ->
softreset(M) -> postreset(M) -> postreset(S)
Note that softreset is called only for the master. Softreset resets
both M/S by definition, so SRST on master should handle both (the
standard method will work just fine).
As slave_link excludes PMP support and only code paths which deal with
the attributes of physical link are affected, all the changes are
localized to libata.h, libata-core.c and libata-eh.c.
* ata_is_host_link() updated so that slave_link is considered as host
link too.
* iterator extended to iterate over the slave_link when using the
underbarred version.
* force param handling updated such that devno 16 is mapped to the
slave link/device.
* ata_link_on/offline() updated to return the combined result from
master and slave link. ata_phys_link_on/offline() are the direct
versions.
* EH autopsy and report are performed separately for master slave
links. Reset is udpated to implement the above described reset
sequence.
Except for reset update, most changes are minor, many of them just
modifying dev->link to ata_dev_phys_link(dev) or using phys online
test instead.
After this update, LLDs can take full advantage of per-dev SCR
registers by simply turning on slave link.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Implement __ata_port_next_link() and reimplement
__ata_port_for_each_link() and ata_port_for_each_link() using it.
This removes relatively large inlined code and makes iteration easier
to extend.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Logically, SCR access ops should take @link; however, there was no
compelling reason to convert all SCR access ops when adding @link
abstraction as there's one-to-one mapping between a port and a non-PMP
link. However, that assumption won't hold anymore with the scheduled
addition of slave link.
Make SCR access ops per-link.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Dave Müller sent a diff for the pata_oldpiix that highlighted a problem
where a lot of the ATA drivers assume dma_mode == 0 means "no DMA" while
the core code uses 0xFF.
This turns out to have other consequences such as code doing >= XFER_UDMA_0
also catching 0xFF as UDMAlots. Fortunately it doesn't generally affect
set_dma_mode, although some drivers call back into their own set mode code
from other points.
Having been through the drivers I've added helpers for using_udma/using_mwdma
dma_enabled so that people don't open code ranges that may change (eg if UDMA8
appears somewhere)
Thanks to David for the initial bits
[and added fix for pata_oldpiix from and signed-off-by Dave Mueller
<dave.mueller@gmx.ch> -jg]
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Save SControl during probing and restore it on detach. This prevents
adjustments made by libata drivers to seep into the next driver which
gets attached (be it a libata one or not).
It's not clear whether SControl also needs to be restored on suspend.
The next system to have control (ACPI or kexec'd kernel) would
probably like to see the original SControl value but there's no
guarantee that a link is gonna keep working after SControl is adjusted
without a reset and adding a reset and modified recovery cycle soley
for this is an overkill. For now, do it only for detach.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Implement force params nohrst, nosrst and norst. This is to work
around reset related problems and ease debugging.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
