ncr5380: Remove redundant ICR_ARBITRATION_LOST test and eliminate FLAG_DTC3181E

Remove FLAG_DTC3181E. It was used to suppress a final Arbitration Lost
(SEL asserted) test that isn't actually needed. The test was suppressed
because it causes problems for DTC436 and DTC536 chips. It takes place
after the host wins arbitration, so SEL has been asserted. These chips
can't seem to tell whether it was the host or another bus device that
did so.

This questionable final test appears in a flow chart in an early NCR5380
datasheet. It was removed from later documents like the DP5380 datasheet.

By the time this final test takes place, the driver has already tested
the Arbitration Lost bit several times. The first test happens 3 us after
BUS FREE (or longer due to register access delays). The protocol requires
that a device stop signalling within 1.8 us after BUS FREE unless it won
arbitration, in which case it must assert SEL, which is detected 1.2 us
later by the first Arbitration Lost test.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
diff --git a/drivers/scsi/NCR5380.c b/drivers/scsi/NCR5380.c
index be40c96..a4defd1 100644
--- a/drivers/scsi/NCR5380.c
+++ b/drivers/scsi/NCR5380.c
@@ -528,14 +528,13 @@
 	         "base 0x%lx, irq %d, "
 	         "can_queue %d, cmd_per_lun %d, "
 	         "sg_tablesize %d, this_id %d, "
-	         "flags { %s%s%s%s}, "
+	         "flags { %s%s%s}, "
 	         "options { %s} ",
 	         instance->hostt->name, instance->io_port, instance->n_io_port,
 	         instance->base, instance->irq,
 	         instance->can_queue, instance->cmd_per_lun,
 	         instance->sg_tablesize, instance->this_id,
 	         hostdata->flags & FLAG_NO_DMA_FIXUP  ? "NO_DMA_FIXUP "  : "",
-	         hostdata->flags & FLAG_DTC3181E      ? "DTC3181E "      : "",
 	         hostdata->flags & FLAG_NO_PSEUDO_DMA ? "NO_PSEUDO_DMA " : "",
 	         hostdata->flags & FLAG_TOSHIBA_DELAY ? "TOSHIBA_DELAY "  : "",
 #ifdef AUTOPROBE_IRQ
@@ -1159,17 +1158,6 @@
 	NCR5380_write(INITIATOR_COMMAND_REG,
 		      ICR_BASE | ICR_ASSERT_SEL | ICR_ASSERT_BSY);
 
-	if (!(hostdata->flags & FLAG_DTC3181E) &&
-	    /* RvC: DTC3181E has some trouble with this
-	     *      so we simply removed it. Seems to work with
-	     *      only Mustek scanner attached
-	     */
-	    (NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST)) {
-		NCR5380_write(MODE_REG, MR_BASE);
-		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
-		dprintk(NDEBUG_ARBITRATION, "scsi%d : lost arbitration, deasserting ICR_ASSERT_SEL\n", instance->host_no);
-		return -1;
-	}
 	/* 
 	 * Again, bus clear + bus settle time is 1.2us, however, this is 
 	 * a minimum so we'll udelay ceil(1.2)