linux-stable.git/drivers/scsi/atari_scsi.c, branch v4.2

ncr5380: Drop owner assignment from platform_drivers

2015-03-09T11:18:14+00:00

This platform_driver does not need to set an owner, it will be populated by
the driver core.

Signed-off-by: Wolfram Sang 
Signed-off-by: Finn Thain 
Signed-off-by: James Bottomley

atari_NCR5380: Move static co-routine variables to host data

2014-11-20T08:11:20+00:00

Unlike NCR5380.c, the atari_NCR5380.c core driver is limited to a single
instance because co-routine state is stored globally.

Fix this by removing the static scsi host pointer. For the co-routine,
obtain this pointer from the work_struct pointer instead. For the interrupt
handler, obtain it from the dev_id argument.

Signed-off-by: Finn Thain 
Reviewed-by: Hannes Reinecke 
Tested-by: Michael Schmitz 
Signed-off-by: Christoph Hellwig

atari_NCR5380: Introduce FLAG_TAGGED_QUEUING

2014-11-20T08:11:19+00:00

The static variable setup_use_tagged_queuing is declared in mac_scsi.c,
sun3_scsi.c and atari_scsi.c and doesn't belong in the core driver.
None of the other NCR5380 drivers suffer from this layering issue which
makes merging the core drivers more difficult and will likely hinder plans
for future use of platform data to configure the driver.

Replace the static variable with a host flag. This way it can be reported
along with the other flags.

Signed-off-by: Finn Thain 
Reviewed-by: Hannes Reinecke 
Tested-by: Michael Schmitz 
Signed-off-by: Christoph Hellwig

atari_NCR5380: Merge from sun3_NCR5380.c

2014-11-20T08:11:17+00:00

There is very little difference between the sun3_NCR5380.c core driver
and atari_NCR5380.c. The former is a fork of the latter.

Merge the sun3_NCR5380.c core driver into atari_NCR5380.c so that
sun3_scsi.c can adopt the latter and the former can be deleted.

Signed-off-by: Finn Thain 
Reviewed-by: Hannes Reinecke 
Tested-by: Michael Schmitz 
Signed-off-by: Christoph Hellwig

atari_NCR5380: Refactor Falcon locking

2014-11-20T08:11:17+00:00

Simplify falcon_release_lock_if_possible() by making callers responsible for
disabling local IRQ's, which they must do anyway to correctly synchronize
the ST DMA "lock" with core driver data structures. Move this
synchronization logic to the core driver with which it is tightly coupled.

Other LLD's like sun3_scsi and mac_scsi that can make use of this core
driver can just stub out the NCR5380_acquire_dma_irq() and
NCR5380_release_dma_irq() calls so the compiler will eliminate the
ST DMA code.

Remove a redundant local_irq_save/restore pair (irq's are disabled for
interrupt handlers these days). Revise the locking for
atari_scsi_bus_reset(): use local_irq_save/restore() instead of
atari_turnoff/turnon_irq(). There is no guarantee that atari_scsi still
holds the ST DMA lock during EH, so atari_turnoff/turnon_irq() could
end up dropping an IDE or floppy interrupt.

Signed-off-by: Finn Thain 
Tested-by: Michael Schmitz 
Reviewed-by: Hannes Reinecke 
Signed-off-by: Christoph Hellwig

atari_NCR5380: Refactor Falcon special cases

2014-11-20T08:11:16+00:00

Make the atari_NCR5380.c core driver usable by sun3_scsi, mac_scsi and
others by moving some of the Falcon-specific code out of the core driver:
!IS_A_TT, atari_read_overruns and falcon_dont_release. Replace these with
hostdata variables and flags. FLAG_CHECK_LAST_BYTE_SENT is unused in
atari_NCR5380.c so don't set it.

Signed-off-by: Finn Thain 
Reviewed-by: Hannes Reinecke 
Tested-by: Michael Schmitz 
Signed-off-by: Christoph Hellwig

ncr5380: Remove ENABLE_IRQ/DISABLE_IRQ macros

2014-11-20T08:11:16+00:00

atari_NCR5380.c enables its IRQ when it is already enabled. Sun3 doesn't
use the ENABLE_IRQ/DISABLE_IRQ cruft. Remove it.

Signed-off-by: Finn Thain 
Reviewed-by: Hannes Reinecke 
Tested-by: Michael Schmitz 
Signed-off-by: Christoph Hellwig

atari_scsi: Remove header

2014-11-20T08:11:14+00:00

The #defines in atari_scsi.h are intended to influence subsequent #includes
in atari_scsi.c. IMHO, that's too convoluted.

Remove atari_scsi.h by moving those macro definitions to atari_scsi.c,
consistent with other NCR5380 drivers.

Signed-off-by: Finn Thain 
Reviewed-by: Hannes Reinecke 
Tested-by: Michael Schmitz 
Signed-off-by: Christoph Hellwig

atari_scsi: Convert to platform device

2014-11-20T08:11:14+00:00

Convert atari_scsi to platform device and eliminate scsi_register().

Validate __setup options later on so that module options are checked as well.

Remove the comment about the scsi mid-layer disabling the host irq as it
is no longer true (AFAICT). Also remove the obsolete slow interrupt stuff
(IRQ_TYPE_SLOW == 0 anyway).

Signed-off-by: Finn Thain 
Reviewed-by: Hannes Reinecke 
Tested-by: Michael Schmitz 
Acked-by: Geert Uytterhoeven 
Signed-off-by: Christoph Hellwig

atari_scsi: Fix atari_scsi deadlocks on Falcon

2014-11-20T08:11:13+00:00

Don't disable irqs when waiting for the ST DMA "lock"; its release may
require an interrupt.

Introduce stdma_try_lock() for use in soft irq context. atari_scsi now tells
the SCSI mid-layer to defer queueing a command if the ST DMA lock is not
available, as per Michael's patch:
http://marc.info/?l=linux-m68k&m=139095335824863&w=2

The falcon_got_lock variable is race prone: we can't disable IRQs while
waiting to acquire the lock, so after acquiring it there must be some
interval during which falcon_got_lock remains false. Introduce
stdma_is_locked_by() to replace falcon_got_lock.

The falcon_got_lock tests in the EH handlers are incorrect these days. It
can happen that an EH handler is called after a command completes normally.
Remove these checks along with falcon_got_lock.

Also remove the complicated and racy fairness wait queues. If fairness is an
issue (when SCSI competes with IDE for the ST DMA interrupt), the solution
is likely to be a lower value for host->can_queue.

Signed-off-by: Finn Thain 
Reviewed-by: Hannes Reinecke 
Tested-by: Michael Schmitz 
Acked-by: Geert Uytterhoeven 
Signed-off-by: Christoph Hellwig