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  1. 19 May, 2010 2 commits
    • Tejun Heo's avatar
      libata-sff: clean up BMDMA initialization · c7087652
      Tejun Heo authored 
      When BMDMA initialization failed or BMDMA was not available for
whatever reason, bmdma_addr was left at zero and used as an indication
that BMDMA shouldn't be used.  This leads to the following problems.

p1. For BMDMA drivers which don't use traditional BMDMA register,
    ata_bmdma_mode_filter() incorrectly inhibits DMA modes.  Those
    drivers either have to inherit from ata_sff_port_ops or clear
    ->mode_filter explicitly.

p2. non-BMDMA drivers call into BMDMA PRD table allocation.  It
    doesn't actually allocate PRD table if bmdma_addr is not
    initialized but is still confusing.

p3. For BMDMA drivers which don't use traditional BMDMA register, some
    methods might not be invoked as expected (e.g. bmdma_stop from
    ata_sff_post_internal_cmd()).

p4. SFF drivers w/ custom DMA interface implement noop BMDMA ops
    worrying libata core might call into one of them.

These problems are caused by the muddy line between SFF and BMDMA and
the assumption that all BMDMA controllers initialize bmdma_addr.

This patch fixes p1 and p2 by removing the bmdma_addr assumption and
moving prd allocation to BMDMA port start.  Later patches will fix the
remaining issues.

This patch improves BMDMA initialization such that

* When BMDMA register initialization fails, falls back to PIO instead
  of failing.  ata_pci_bmdma_init() never fails now.

* When ata_pci_bmdma_init() falls back to PIO, it clears
  ap->mwdma_mask and udma_mask instead of depending on
  ata_bmdma_mode_filter().  This makes ata_bmdma_mode_filter()
  unnecessary thus resolving p1.

* ata_port_start() which actually is BMDMA specific is moved to
  ata_bmdma_port_start().  ata_port_start() and ata_sff_port_start()
  are killed.

* ata_sff_port_start32() is moved and renamed to
  ata_bmdma_port_start32().

Drivers which no longer call into PRD table allocation are...

  pdc_adma, sata_inic162x, sata_qstor, sata_sx4, pata_cmd640 and all
  drivers which inherit from ata_sff_port_ops.

pata_icside sets ->port_start to ATA_OP_NULL as it doesn't need PRD
but is a BMDMA controller and doesn't have custom port_start like
other such controllers.

Note that with the previous patch which makes all and only BMDMA
drivers inherit from ata_bmdma_port_ops, this change doesn't break
drivers which need PRD table.
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarJeff Garzik <jgarzik@redhat.com>
      c7087652
    • Tejun Heo's avatar
      libata-sff: clean up inheritance in several drivers · 8930ff25
      Tejun Heo authored 
      1. pata_cmd640 is PIO only.  Inherit from sff.

2. pata_macio is BMDMA.  Inherit from bmdma and drop explicit
   bmdma_mode_filter() setting.

3. In sata_mv, unlike mv5, mv6 is BMDMA.  Inherit from bmdma and
   don't clear ->post_internal_cmd().

4. bf54x and icside are quasi-BMDMA controllers which don't use the
   standard BMDMA registers so they don't initialize bmdma_addr and
   inherit from sff to avoid the default mode_filter which disables
   DMA modes if bmdma_addr is not initialized.

For 2 and 3, this patch makes the drivers explicitly specify
->mode_filter to ATA_OP_NULL while inheriting from ata_bmdma_port_ops.
These will be removed by the next patch.

This patch makes all and only BMDMA drivers inherit from
ata_bmdma_port_ops to ease further SFF/BMDMA separation.
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarJeff Garzik <jgarzik@redhat.com>
      8930ff25
  3. 18 May, 2010 3 commits
  5. 15 May, 2010 8 commits
  7. 14 May, 2010 27 commits
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