aic79xx.c:

aic79xx.c:
	Allow 500us between pauses in ahd_pause_and_flushwork().
	The maximum we will wait is now 500ms.

	In the same routine, remove any attempt to clear ENSELO.
	Let the firmware do it once the current selection has
	completed.  This avoids some race conditions having to
	do with non-packetized completions and the auto-clearing
	of ENSELO on packetized completions.

	Also avoid attempts to clear critical sections when
	interrups are pending.  We are going to loop again
	anyway, so clearing critical sections is a waste of
	time.  It also may not be possible to clear a critical
	section if the source of the interrupt was a SEQINT.

aic79xx_pci.c:
	Use the Generic 9005 mask when looking for generic 7901B
	parts.  This allows the driver to attach to 7901B parts
	on motherboards using a non-Adaptec subvendor ID.

aic79xx_inline.h:
	Test for the SCBRAM_RD_BUG against the bugs
	field, not the flags field in the softc.

aic79xx.c:
	Cancel pending transactions on devices that
	respond with a selection timeout.  This decreases
	the duration of timeout recovery when a device
	disappears.

aic79xx.c:
	Don't bother forcing renegotiation on a selection
	timeout now that we use the device reset handler
	to abort any pending commands on the target.
	The device reset handler already takes us down
	to async narrow and forces a renegotiation.

	In the device reset handlers, only send a
	BDR sent async event if the status is not
	CAM_SEL_TIMEOUT.  This avoids sending this
	event in the selection timeout case

aic79xx.c:
	Modify the Core timeout handler to verify that another
	command has the potential to timeout before passing off
	a command timeout as due to some other command.  This
	safety measure is added in response to a timeout recovery
	failure on H2B where it appears that incoming reselection
	status was lost during a drive pull test.  In that case,
	the recovery handler continued to wait for the command
	that was active on the bus indefinetly.  While the root
	cause of the above issue is still being determined seems
	a prudent safeguard.

aic79xx_pci.c:
	Add a specific probe entry for the Dell OEM 39320(B).

aic79xx.c:
aic79xx.h:
aic79xx.reg:
aic79xx.seq:
	Modify the aic79xx firmware to never cross a cacheline or
	ADB boundary when DMA'ing completion entries to the host.
	In PCI mode, at least in 32/33 configurations, the SCB
	DMA engine may lose its place in the data-stream should
	the target force a retry on something other than an
	8byte aligned boundary. In PCI-X mode, we do this to
	avoid split transactions since many chipsets seem to be
	unable to format proper split completions to continue
	the data transfer.

	The above change allows us to drop our completion entries
	from 8 bytes to 4.  We were using 8 byte entries to ensure
	that PCI retries could only occur on an 8byte aligned
	boundary.  Now that the sequencer guarantees this by splitting
	up completions, we can safely drop the size to 4 bytes (2
	byte tag, one byte SG_RESID, one byte pad).

	Both the split-completion and PCI retry problems only show
	up under high tag load when interrupt coalescing is being
	especially effective.  The switch from a 2byte completion
	entry to an 8 byte entry to solve the PCI problem increased
	the chance of incurring a split in PCI-X mode when multiple
	transactions were completed at once.  Dropping the completion
	size to 4 bytes also means that we can complete more commands
	in a single DMA (128byte FIFO -> 32 commands instead of 16).

aic79xx.c:
	Modify the SCSIINT handler to defer clearing
	sequencer critical sections to the individual
	interrupt handlers.  This allows us to
	immediately disable any outgoing selections in
	the case of an unexpected busfree so we don't
	inadvertantly clear ENSELO *after* a new selection
	has started.  Doing so may cause the sequencer
	to miss a successful selection.

	In ahd_update_pending_scbs(), only clear ENSELO if
	the bus is currently busy and a selection is not
	already in progress or the sequencer has yet to
	handle a pending selection.  While we want to ensure
	that the selection for the SCB at the head of the
	selection queue is restarted so that any change in
	negotiation request can take effect, we can't clobber
	pending selection state without confusing the sequencer
	into missing a selection.

Obtained-from: FreeBSD