Skip to content

L
linux
Switch branch/tag
  1. 17 Apr, 2008 13 commits
    • Tejun Heo's avatar
      libata: implement and use ops inheritance · 029cfd6b
      Tejun Heo authored 
      libata lets low level drivers build ata_port_operations table and
register it with libata core layer.  This allows low level drivers
high level of flexibility but also burdens them with lots of
boilerplate entries.

This becomes worse for drivers which support related similar
controllers which differ slightly.  They share most of the operations
except for a few.  However, the driver still needs to list all
operations for each variant.  This results in large number of
duplicate entries, which is not only inefficient but also error-prone
as it becomes very difficult to tell what the actual differences are.

This duplicate boilerplates all over the low level drivers also make
updating the core layer exteremely difficult and error-prone.  When
compounded with multi-branched development model, it ends up
accumulating inconsistencies over time.  Some of those inconsistencies
cause immediate problems and fixed.  Others just remain there dormant
making maintenance increasingly difficult.

To rectify the problem, this patch implements ata_port_operations
inheritance.  To allow LLDs to easily re-use their own ops tables
overriding only specific methods, this patch implements poor man's
class inheritance.  An ops table has ->inherits field which can be set
to any ops table as long as it doesn't create a loop.  When the host
is started, the inheritance chain is followed and any operation which
isn't specified is taken from the nearest ancestor which has it
specified.  This operation is called finalization and done only once
per an ops table and the LLD doesn't have to do anything special about
it other than making the ops table non-const such that libata can
update it.

libata provides four base ops tables lower drivers can inherit from -
base, sata, pmp, sff and bmdma.  To avoid overriding these ops
accidentaly, these ops are declared const and LLDs should always
inherit these instead of using them directly.

After finalization, all the ops table are identical before and after
the patch except for setting .irq_handler to ata_interrupt in drivers
which didn't use to.  The .irq_handler doesn't have any actual effect
and the field will soon be removed by later patch.

* sata_sx4 is still using old style EH and currently doesn't take
  advantage of ops inheritance.
Signed-off-by: default avatarTejun Heo <htejun@gmail.com>
      029cfd6b
    • Tejun Heo's avatar
      libata: implement and use SHT initializers · 68d1d07b
      Tejun Heo authored 
      libata lets low level drivers build scsi_host_template and register it
to the SCSI layer.  This allows low level drivers high level of
flexibility but also burdens them with lots of boilerplate entries.

This patch implements SHT initializers which can be used to initialize
all the boilerplate entries in a sht.  Three variants of them are
implemented - BASE, BMDMA and NCQ - for different types of drivers.
Note that entries can be overriden by putting individual initializers
after the helper macro.

All sht tables are identical before and after this patch.
Signed-off-by: default avatarTejun Heo <htejun@gmail.com>
      68d1d07b
    • Tejun Heo's avatar
      libata: normalize port_info, port_operations and sht tables · 6bd99b4e
      Tejun Heo authored 
      Over the time, port info, ops and sht structures developed quite a bit
of inconsistencies.  This patch updates drivers.

* Enable/disable_pm callbacks added to all ahci ops tables.

* Every driver for SFF controllers now uses ata_sff_port_start()
  instead of ata_port_start() unless the driver has custom
  implementation.

* Every driver for SFF controllers now uses ata_pci_default_filter()
  unless the driver has custom implementation.

* Removed an odd port_info->sht initialization from ata_piix.c.
  Likely a merge byproduct.

* A port which has ATA_FLAG_SATA set doesn't need to set cable_detect
  to ata_cable_sata().  Remove it from via and mv port ops.

* Some drivers had unnecessary .max_sectors initialization which is
  ignored and was missing .slave_destroy callback.  Fixed.

* Removed unnecessary sht initializations port_info's.

* Removed onsolete scsi device suspend/resume callbacks from
  pata_bf54x.

* No reason to set ata_pci_default_filter() and bmdma functions for
  PIO-only drivers.  Remove those callbacks and replace
  ata_bmdma_irq_clear with ata_noop_irq_clear.

* pata_platform sets port_start to ata_dummy_ret0.  port_start can
  just be set to NULL.

* sata_fsl supports NCQ but was missing qc_defer.  Fixed.

* pata_rb600_cf implements dummy port_start.  Removed.
Signed-off-by: default avatarTejun Heo <htejun@gmail.com>
      6bd99b4e
    • Tejun Heo's avatar
      libata: implement and use ata_noop_irq_clear() · 358f9a77
      Tejun Heo authored 
      ->irq_clear() is used to clear IRQ bit of a SFF controller and isn't
useful for drivers which don't use libata SFF HSM implementation.
However, it's a required callback and many drivers implement their own
noop version as placeholder.  This patch implements ata_noop_irq_clear
and use it to replace those custom placeholders.

Also, SFF drivers which don't support BMDMA don't need to use
ata_bmdma_irq_clear().  It becomes noop if BMDMA address isn't
initialized.  Convert them to use ata_noop_irq_clear().
Signed-off-by: default avatarTejun Heo <htejun@gmail.com>
      358f9a77
    • Tejun Heo's avatar
      libata: reorganize ata_port_operations · c1bc899f
      Tejun Heo authored 
      Over the time, ops in ata_port_operations has become a bit confusing.
Reorganize.  SFF/BMDMA ops are separated into separate a group as they
will be taken out of ata_port_operations later.
Signed-off-by: default avatarTejun Heo <htejun@gmail.com>
      c1bc899f
    • Tejun Heo's avatar
      libata: PCI device should be powered up before being accessed · f08048e9
      Tejun Heo authored 
      PCI device should be powered up or powered up before its PCI regsiters
are accessed.  Although PCI configuration register access is allowed
in D3hot, PCI device is free to reset its status when transiting from
D3hot to D0 causing configuration data to change.

Many libata SFF drivers which use ata_pci_init_one() read and update
configuration registers before calling ata_pci_init_one() which
enables the PCI device.  Also, in resume paths, some drivers access
registers without resuming the PCI device.

This patch adds a call to pcim_enable_device() in init path if
register is accessed before calling ata_pci_init_one() and make resume
paths first resume PCI devices, access PCI configuration regiters then
resume ATA host.

While at it...

* cmd640 was strange in that it set ->resume even when CONFIG_PM is
  not.  This is by-product of minimal build fix.  Updated.

* In cs5530, Don't BUG() on reinit failure.  Just whine and fail
  resume.
Signed-off-by: default avatarTejun Heo <htejun@gmail.com>
      f08048e9
    • Tejun Heo's avatar
      libata: kill ata_ehi_schedule_probe() · b558eddd
      Tejun Heo authored 
      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: default avatarTejun Heo <htejun@gmail.com>
      b558eddd
    • Tejun Heo's avatar
      libata: kill ATA_LFLAG_SKIP_D2H_BSY · 8cebf274
      Tejun Heo authored 
      Some controllers can't reliably record the initial D2H FIS after SATA
link is brought online for whatever reason.  Advanced controllers
which don't have traditional TF register based interface often have
this problem as they don't really have the TF registers to update
while the controller and link are being initialized.

SKIP_D2H_BSY works around the problem by skipping the wait for device
readiness before issuing SRST, so for such controllers libata issues
SRST blindly and hopes for the best.

Now that libata defaults to hardreset, this workaround is no longer
necessary.  For controllers which have support for hardreset, SRST is
never issued by itself.  It is only issued as follow-up SRST for
device classification and PMP initialization, so there's no need to
wait for it from prereset.

Kill ATA_LFLAG_SKIP_D2H_BSY.
Signed-off-by: default avatarTejun Heo <htejun@gmail.com>
      8cebf274
    • Tejun Heo's avatar
      libata: kill ATA_EHI_RESUME_LINK · 672b2d65
      Tejun Heo authored 
      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: default avatarTejun Heo <htejun@gmail.com>
      672b2d65
    • Tejun Heo's avatar
      libata: kill ATA_LFLAG_HRST_TO_RESUME · d692abd9
      Tejun Heo authored 
      Now that hardreset is the preferred method of resetting, there's no
need for ATA_LFLAG_HRST_TO_RESUME flag.  Kill it.
Signed-off-by: default avatarTejun Heo <htejun@gmail.com>
      d692abd9
    • Tejun Heo's avatar
      libata: prefer hardreset · cf480626
      Tejun Heo authored 
      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: default avatarTejun Heo <htejun@gmail.com>
      cf480626
    • Linus Torvalds's avatar
      Linux 2.6.25 · 4b119e21
      Linus Torvalds authored
      4b119e21
    • Linus Torvalds's avatar
      Merge git://git.kernel.org/pub/scm/linux/kernel/git/bart/ide-2.6 · c970d5a3
      Linus Torvalds authored 
      * git://git.kernel.org/pub/scm/linux/kernel/git/bart/ide-2.6:
  it821x: do not describe noraid parameter with its value
  Pb1200/DBAu1200: fix bad IDE resource size
  Au1200: IDE driver build fix
  Au1200: kill IDE driver function prototypes
  avr32 mustn't select HAVE_IDE
      c970d5a3
  3. 16 Apr, 2008 27 commits
GitLab Nexedi Edition | About GitLab | About Nexedi | 沪ICP备2021021310号-2 | 沪ICP备2021021310号-7