* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6: (222 commits)
[SCSI] zfcp: Remove flag ZFCP_STATUS_FSFREQ_TMFUNCNOTSUPP
[SCSI] zfcp: Activate fc4s attributes for zfcp in FC transport class
[SCSI] zfcp: Block scsi_eh thread for rport state BLOCKED
[SCSI] zfcp: Update FSF error reporting
[SCSI] zfcp: Improve ELS ADISC handling
[SCSI] zfcp: Simplify handling of ct and els requests
[SCSI] zfcp: Remove ZFCP_DID_MASK
[SCSI] zfcp: Move WKA port to zfcp FC code
[SCSI] zfcp: Use common code definitions for FC CT structs
[SCSI] zfcp: Use common code definitions for FC ELS structs
[SCSI] zfcp: Update FCP protocol related code
[SCSI] zfcp: Dont fail SCSI commands when transitioning to blocked fc_rport
[SCSI] zfcp: Assign scheduled work to driver queue
[SCSI] zfcp: Remove STATUS_COMMON_REMOVE flag as it is not required anymore
[SCSI] zfcp: Implement module unloading
[SCSI] zfcp: Merge trace code for fsf requests in one function
[SCSI] zfcp: Access ports and units with container_of in sysfs code
[SCSI] zfcp: Remove suspend callback
[SCSI] zfcp: Remove global config_mutex
[SCSI] zfcp: Replace local reference counting with common kref
...
This patch modifies scsi_host_template->change_queue_depth so that
it takes an argument indicating why it is being called. This will be
used so that if a LLD needs to do some extra processing when
handling queue fulls or later ramp ups, it can do so.
This is a simple port of the drivers setting a change_queue_depth
callback. In the patch I just have these LLDs adjust the queue depth
if the user was requesting it.
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
[Vasu.Dev: v2
Also converted pmcraid_change_queue_depth and then verified
all modules compile using "make allmodconfig" for any new build
warnings on X86_64.
Updated original description after combing two original
patches from Mike to make this patch git bisectable.]
Signed-off-by: Vasu Dev <vasu.dev@intel.com>
[jejb: fixed up 53c700]
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
ata_set_lba_range_entries used the variable max for two different things
which was confusing. Make the function take a buffer size in bytes as
argument and return the used buffer size upon completion.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Our current TRIM payload is a single sector that can accommodate 64 *
65535 blocks being unmapped. Report this value in the Block Limits
Maximum Unmap LBA count field.
If a storage device supports TRIM and the DRAT and RZAT bits are set,
report TPRZ=1 in Read Capacity(16).
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Add support for the ATA TRIM command in libata. We translate a WRITE SAME 16
command with the unmap bit set into an ATA TRIM command and export enough
information in READ CAPACITY 16 and the block limits EVPD page so that the new
SCSI layer discard support will driver this for us.
Note that I hardcode the WRITE_SAME_16 opcode for now as the patch to introduce
the symbolic is not in 2.6.32 yet but only in the SCSI tree - as soon as it is
merged we can fix it up to properly use the symbolic name.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
sysfs attributes shouldn't require newlines. Make it possible to set the
link power management policy without a trailing newline.
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
ata_scsi_pass_thru() was checking for input sanity and disallowed
commands while initializaing qc from scmd. TPM filtering was added
right after protocol check at which point tf wasn't initialized
properly. This means that TPM filtering has never really worked.
This patch fixes the bug by reorganizing ata_scsi_pass_thru() such
that qc is fully initialized before checking for invalid conditions
which is way less error prone.
Discovered while Thilo-Alexander Ginkel was trying debug patches for
bko#13416.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Thilo-Alexander Ginkel <thilo@ginkel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Now that the SCSI disk driver correctly handles non-rotational devices
we can move setting the queue flag to SCSI.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
This was a hack to give userland shutdown tools time to drop manual
spindown. All popular distros updated quite some time ago and the due
is well passed. Drop it.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jaswinder Singh Rajput <jaswinder@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
This patch provides new heuristics for parsing both the form factor and
media rotation rate ATA IDENFITY words.
The reported ATA version must be 7 or greater and the device must return
values defined as valid in the standard. Only then are the
characteristics reported to SCSI via the VPD B1 page.
This seems like a reasonable compromise to me considering that we have
been shipping several kernel releases that key off the rotation rate bit
without any version checking whatsoever. With no complaints so far.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
For disks with 4KB sectors, report the correct block size and alignment
when filling out the READ CAPACITY(16) response.
This patch is based upon code from Matthew Wilcox' 4KB ATA tree. I
fixed the bug I reported a while back caused by ATA and SCSI using
different approaches to describing the alignment.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
With recent unification of fields, it's now guaranteed that
rq->data_len always equals blk_rq_bytes(). Convert all non-IDE direct
users to accessors. IDE will be converted in a separate patch.
Boaz: spotted incorrect data_len/resid_len conversion in osd.
[ Impact: convert direct rq->data_len usages to blk_rq_bytes() ]
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Cc: Pete Zaitcev <zaitcev@redhat.com>
Cc: Eric Moore <Eric.Moore@lsi.com>
Cc: Markus Lidel <Markus.Lidel@shadowconnect.com>
Cc: Darrick J. Wong <djwong@us.ibm.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Eric Moore <Eric.Moore@lsi.com>
Cc: Boaz Harrosh <bharrosh@panasas.com>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
The legacy old IDE ioctl API for this is a bit primitive so we try
and map stuff sensibly onto it.
- Set PIO over DMA devices to report 32bit
- Add ability to change the PIO32 settings if the controller permits it
- Add that functionality into the sff drivers
- Add that functionality into the VLB legacy driver
- Turn on the 32bit PIO on the ninja32 and add support there
Signed-off-by: Alan Cox <alan@linux.intel.com>
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>
Introduce new libata flags ATA_FLAG_NO_POWEROFF_SPINDOWN and
ATA_FLAG_NO_HIBERNATE_SPINDOWN that, if set, will prevent disks from
being spun off during system power off and hibernation, respectively
(to handle the hibernation case we need the new system state
SYSTEM_HIBERNATE_ENTER that can be checked against by libata, in
analogy with SYSTEM_POWER_OFF).
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
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>
scsi_execute() and scsi_execute_req() discard the residual length
information. Some callers need it. This adds residual argument
(optional) to scsi_execute and scsi_execute_req.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.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>
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>
Peter Moulder has pointed out that there is a slight chance that a
negative value might be passed to jiffies_to_msecs() in
ata_scsi_park_show(). This is fixed by saving the value of jiffies in a
local variable, thus also reducing code since the volatile variable
jiffies is accessed only once.
Signed-off-by: Elias Oltmanns <eo@nebensachen.de>
Signed-off-by: Tejun Heo <tj.kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
For devices behind sata port multipliers, we have to make sure that
they share a tag map since all tags for that PMP must be unique.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
The recent commit 2fca5ccf97 ("libata:
switch to using block layer tagging support") to enable support for
block layer tagging in libata was broken for non-NCQ devices
The block layer initializes the tag field to -1 to detect invalid uses
of a tag, and if the libata devices does NOT support NCQ, we just used
that field to index the internal command list. So we need to check for
-1 first and only use the tag field if it's valid.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Reported-by: Alexander Beregalov <a.beregalov@gmail.com>
Tested-by: Paul Mundt <lethal@linux-sh.org>
Tested-by: Dave Young <hidave.darkstar@gmail.com>
Tested-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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>
* 'for-2.6.28' of git://git.kernel.dk/linux-2.6-block: (132 commits)
doc/cdrom: Trvial documentation error, file not present
block_dev: fix kernel-doc in new functions
block: add some comments around the bio read-write flags
block: mark bio_split_pool static
block: Find bio sector offset given idx and offset
block: gendisk integrity wrapper
block: Switch blk_integrity_compare from bdev to gendisk
block: Fix double put in blk_integrity_unregister
block: Introduce integrity data ownership flag
block: revert part of d7533ad0e132f92e75c1b2eb7c26387b25a583c1
bio.h: Remove unused conditional code
block: remove end_{queued|dequeued}_request()
block: change elevator to use __blk_end_request()
gdrom: change to use __blk_end_request()
memstick: change to use __blk_end_request()
virtio_blk: change to use __blk_end_request()
blktrace: use BLKTRACE_BDEV_SIZE as the name size for setup structure
block: add lld busy state exporting interface
block: Fix blk_start_queueing() to not kick a stopped queue
include blktrace_api.h in headers_install
...
SSD devices should give an RPM setting of 1 in word 217 of the ID
page. If we see such a device, tell the block layer about it.
Signed-off-by: Jens Axboe <jens.axboe@oracle.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>
Global and per-LLD ATAPI disable checks were done in the command issue
path probably because it was left out during EH conversion. On
affected machines, this can cause lots of warning messages. Move them
to where they belong - the probing path.
Reported by Chunbo Luo.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Chunbo Luo <chunbo.luo@windriver.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev:
AHCI: Remove an unnecessary flush from ahci_qc_issue
AHCI: speed up resume
[libata] Add support for VPD page b1
ata: endianness annotations in pata drivers
libata-eh: update atapi_eh_request_sense() to take @dev instead of @qc
[libata] sata_svw: update code comments relating to data corruption
libata/ahci: enclosure management support
libata: improve EH internal command timeout handling
libata: use ULONG_MAX to terminate reset timeout table
libata: improve EH retry delay handling
libata: consistently use msecs for time durations
SCSI VPD page b1 reports the nominal rotation speed and physical size
of the device. Devices that conform to ATA-8 can return this information
in words 217 and 168 of the identify data.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Add Enclosure Management support to libata and ahci.
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
This adds blk_queue_update_dma_pad to prevent LLDs from overwriting
the dma pad mask wrongly (we added blk_queue_update_dma_alignment due
to the same reason).
This also converts libata to use blk_queue_update_dma_pad instead of
blk_queue_dma_pad.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Tejun Heo <htejun@gmail.com>
Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
There's no reason to check whether to use DMA or not for no data
commands. Don't do it. While at it, make local variable using_pio in
atapi_xlat() set iff ATAPI_PROT_PIO is going to be used and rename
ata_check_atapi_dma() to atapi_check_dma() for consistency.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Fix libata-scsi kernel-doc notation:
Warning(linux-2.6.25-git15//drivers/ata/libata-scsi.c:1659): No description found for parameter 'cmd'
Warning(linux-2.6.25-git15//drivers/ata/libata-scsi.c:1971): No description found for parameter 'buf'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
I was hoping ATA_HORKAGE_NODMA | ATA_HORKAGE_SKIP_PM could keep it
happy but no even this doesn't work under certain configurations and
it's not like we can do anything useful with the cofig device anyway.
Replace ATA_HORKAGE_SKIP_PM with ATA_HORKAGE_DISABLE and use it for
the config device. This makes the device completely ignored by
libata.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Buffer length handling in simulated commands is error-prone and full
of bugs. There are a number of places where necessary length checks
are missing and if the output buffer is passed in as sglist, nothing
works.
This patch adds a static buffer ata_scsi_rbuf which is sufficiently
large to handle the larges output from simulated commands (4k
currently), let all simulte functions write to the buffer and removes
all length checks as we know that there always is enough buffer space.
Copying in (for ATAPI inquiry fix up) and out are handled by
sg_copy_to/from_buffer() behind ata_scsi_rbuf_get/put() interface
which handles sglist properly.
This patch is inspired from buffer length check fix patch from Petr
Vandrovec.
Updated to use sg_copy_to/from_buffer() as suggested by FUJITA
Tomonori.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Petr Vandrovec <petr@vmware.com>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* make ata_scsiop_*() static
* make ata_scsi_set_sense() static and move it above its users
* make ata_scsi_rbuf_fill() static
* kill unused ata_scsi_badcmd()
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
It's big, but there doesn't seem to be a way to split it up smaller...
Signed-off-by: Tony Jones <tonyj@suse.de>
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Cc: Roland Dreier <rolandd@cisco.com>
Cc: Sean Hefty <sean.hefty@intel.com>
Cc: Hal Rosenstock <hal.rosenstock@gmail.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6: (137 commits)
[SCSI] iscsi: bidi support for iscsi_tcp
[SCSI] iscsi: bidi support at the generic libiscsi level
[SCSI] iscsi: extended cdb support
[SCSI] zfcp: Fix error handling for blocked unit for send FCP command
[SCSI] zfcp: Remove zfcp_erp_wait from slave destory handler to fix deadlock
[SCSI] zfcp: fix 31 bit compile warnings
[SCSI] bsg: no need to set BSG_F_BLOCK bit in bsg_complete_all_commands
[SCSI] bsg: remove minor in struct bsg_device
[SCSI] bsg: use better helper list functions
[SCSI] bsg: replace kobject_get with blk_get_queue
[SCSI] bsg: takes a ref to struct device in fops->open
[SCSI] qla1280: remove version check
[SCSI] libsas: fix endianness bug in sas_ata
[SCSI] zfcp: fix compiler warning caused by poking inside new semaphore (linux-next)
[SCSI] aacraid: Do not describe check_reset parameter with its value
[SCSI] aacraid: Fix down_interruptible() to check the return value
[SCSI] sun3_scsi_vme: add MODULE_LICENSE
[SCSI] st: rename flush_write_buffer()
[SCSI] tgt: use KMEM_CACHE macro
[SCSI] initio: fix big endian problems for auto request sense
...
The kernel now panics reliably on boot if you have a SATAPI device
connected.
The problem was introduced by the libata merge trying to pull out all
the SFF code into a separate module. Unfortunately, if you're a satapi
device you usually need to call atapi_request_sense, which has a bare
invocation of a SFF callback which is NULL on non-SFF HBAs. Fix this by
making the call conditional.
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Implement helpers to test whether PMP is supported, attached and
determine pmp number to use when issuing SRST to a link. While at it,
move ata_is_host_link() so that it's together with the two new PMP
helpers.
This change simplifies LLDs and helps making PMP support optional.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Now that SFF support is completely separated out from the core layer,
it can be made optional. Add CONFIG_ATA_SFF and let SFF drivers
depend on it. If CONFIG_ATA_SFF isn't set, all codes in libata-sff.c
and data structures for SFF support are disabled. This saves good
number of bytes for small systems.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Add sff_ prefix to SFF specific port ops.
This rename is in preparation of separating SFF support out of libata
core layer. This patch strictly renames ops and doesn't introduce any
behavior difference.
Signed-off-by: Tejun Heo <htejun@gmail.com>
ata_ehi_schedule_probe() was created to hide details of link-resuming
reset magic. Now that all the softreset workarounds are gone,
scheduling probe is very simple - set probe_mask and request RESET.
Kill ata_ehi_schedule_probe() and open code it. This also increases
consistency as ata_ehi_schedule_probe() couldn't cover individual
device probings so they were open-coded even when the helper existed.
While at it, define ATA_ALL_DEVICES as mask of all possible devices on
a link and always use it when requesting probe on link level for
simplicity and consistency. Setting extra bits in the probe_mask
doesn't hurt anybody.
Signed-off-by: Tejun Heo <htejun@gmail.com>
ATA_EHI_RESUME_LINK has two functions - promote reset to hardreset if
ATA_LFLAG_HRST_TO_RESUME is set and preventing EH from shortcutting
reset action when probing is requested. The former is gone now and
the latter can easily be achieved by making EH to perform at least one
reset if reset is requested, which also makes more sense than
depending on RESUME_LINK flag.
As ATA_EHI_RESUME_LINK was the only EHI reset modifier, this also
kills reset modifier handling.
Signed-off-by: Tejun Heo <htejun@gmail.com>
When both soft and hard resets are available, libata preferred
softreset till now. The logic behind it was to be softer to devices;
however, this doesn't really help much. Rationales for the change:
* BIOS may freeze lock certain things during boot and softreset can't
unlock those. This by itself is okay but during operation PHY event
or other error conditions can trigger hardreset and the device may
end up with different configuration.
For example, after a hardreset, previously unlockable HPA can be
unlocked resulting in different device size and thus revalidation
failure. Similar condition can occur during or after resume.
* Certain ATAPI devices require hardreset to recover after certain
error conditions. On PATA, this is done by issuing the DEVICE RESET
command. On SATA, COMRESET has equivalent effect. The problem is
that DEVICE RESET needs its own execution protocol.
For SFF controllers with bare TF access, it can be easily
implemented but more advanced controllers (e.g. ahci and sata_sil24)
require specialized implementations. Simply using hardreset solves
the problem nicely.
* COMRESET initialization sequence is the norm in SATA land and many
SATA devices don't work properly if only SRST is used. For example,
some PMPs behave this way and libata works around by always issuing
hardreset if the host supports PMP.
Like the above example, libata has developed a number of mechanisms
aiming to promote softreset to hardreset if softreset is not going
to work. This approach is time consuming and error prone.
Also, note that, dependingon how you read the specs, it could be
argued that PMP fan-out ports require COMRESET to start operation.
In fact, all the PMPs on the market except one don't work properly
if COMRESET is not issued to fan-out ports after PMP reset.
* COMRESET is an integral part of SATA connection and any working
device should be able to handle COMRESET properly. After all, it's
the way to signal hardreset during reboot. This is the most used
and recommended (at least by the ahci spec) method of resetting
devices.
So, this patch makes libata prefer hardreset over softreset by making
the following changes.
* Rename ATA_EH_RESET_MASK to ATA_EH_RESET and use it whereever
ATA_EH_{SOFT|HARD}RESET used to be used. ATA_EH_{SOFT|HARD}RESET is
now only used to tell prereset whether soft or hard reset will be
issued.
* Strip out now unneeded promote-to-hardreset logics from
ata_eh_reset(), ata_std_prereset(), sata_pmp_std_prereset() and
other places.
Signed-off-by: Tejun Heo <htejun@gmail.com>
