From be3f4121aa352d8fef77a57df4b5e106d7f9a917 Mon Sep 17 00:00:00 2001 From: Finn Thain Date: Sun, 3 Jan 2016 16:05:50 +1100 Subject: 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 Reviewed-by: Hannes Reinecke Tested-by: Ondrej Zary Tested-by: Michael Schmitz Signed-off-by: Martin K. Petersen --- drivers/scsi/atari_NCR5380.c | 9 --------- 1 file changed, 9 deletions(-) (limited to 'drivers/scsi/atari_NCR5380.c') diff --git a/drivers/scsi/atari_NCR5380.c b/drivers/scsi/atari_NCR5380.c index 06245c07ebd2..08e8ace2681b 100644 --- a/drivers/scsi/atari_NCR5380.c +++ b/drivers/scsi/atari_NCR5380.c @@ -1420,15 +1420,6 @@ static int NCR5380_select(struct Scsi_Host *instance, struct scsi_cmnd *cmd) NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_SEL | ICR_ASSERT_BSY); - if ((NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) || - hostdata->connected) { - 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", - HOSTNO); - return -1; - } - /* * Again, bus clear + bus settle time is 1.2us, however, this is * a minimum so we'll udelay ceil(1.2) -- cgit v1.2.3