ncr5380: Remove disused atari_NCR5380.c core driver

Now that atari_scsi and sun3_scsi have been converted to use the NCR5380.c
core driver, remove atari_NCR5380.c. Also remove the last vestiges of its
Tagged Command Queueing implementation from the wrapper drivers.

The TCQ support in atari_NCR5380.c is abandoned by this patch. It is not
merged into the remaining core driver because,

1) atari_scsi defines SUPPORT_TAGS but leaves FLAG_TAGGED_QUEUING disabled
by default, which indicates that it is mostly undesirable.

2) I'm told that it doesn't work correctly when enabled.

3) The algorithm does not make use of block layer tags which it will have
to do because scmd->tag is deprecated.

4) sun3_scsi doesn't define SUPPORT_TAGS at all, yet the the SUPPORT_TAGS
macro interacts with the CONFIG_SUN3 macro in 'interesting' ways.

5) Compile-time configuration with macros like SUPPORT_TAGS caused the
configuration space to explode, leading to untestable and unmaintainable
code that is too hard to reason about.

The merge_contiguous_buffers() code is also abandoned. This was unused
by sun3_scsi. Only atari_scsi used it and then only on TT, because only TT
supports scatter/gather. I suspect that the TT would work fine with
ENABLE_CLUSTERING instead. If someone can benchmark the difference then
perhaps the merge_contiguous_buffers() code can be be justified. Until
then we are better off without the extra complexity.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 1 insertions, 10 deletions

diff --git a/drivers/scsi/atari_scsi.c b/drivers/scsi/atari_scsi.c
index 445c26724ba1..49b7b14e8913 100644
--- a/drivers/scsi/atari_scsi.c
+++ b/drivers/scsi/atari_scsi.c
@@ -87,9 +87,6 @@
 
 /* Definitions for the core NCR5380 driver. */
 
-#define SUPPORT_TAGS
-#define MAX_TAGS                        32
-
 #define NCR5380_implementation_fields   /* none */
 
 #define NCR5380_read(reg)               atari_scsi_reg_read(reg)
@@ -189,8 +186,6 @@ static int setup_cmd_per_lun = -1;
 module_param(setup_cmd_per_lun, int, 0);
 static int setup_sg_tablesize = -1;
 module_param(setup_sg_tablesize, int, 0);
-static int setup_use_tagged_queuing = -1;
-module_param(setup_use_tagged_queuing, int, 0);
 static int setup_hostid = -1;
 module_param(setup_hostid, int, 0);
 static int setup_toshiba_delay = -1;
@@ -479,8 +474,7 @@ static int __init atari_scsi_setup(char *str)
 		setup_sg_tablesize = ints[3];
 	if (ints[0] >= 4)
 		setup_hostid = ints[4];
-	if (ints[0] >= 5)
-		setup_use_tagged_queuing = ints[5];
+	/* ints[5] (use_tagged_queuing) is ignored */
 	/* ints[6] (use_pdma) is ignored */
 	if (ints[0] >= 7)
 		setup_toshiba_delay = ints[7];
@@ -853,9 +847,6 @@ static int __init atari_scsi_probe(struct platform_device *pdev)
 	instance->irq = irq->start;
 
 	host_flags |= IS_A_TT() ? 0 : FLAG_LATE_DMA_SETUP;
-#ifdef SUPPORT_TAGS
-	host_flags |= setup_use_tagged_queuing > 0 ? FLAG_TAGGED_QUEUING : 0;
-#endif
 	host_flags |= setup_toshiba_delay > 0 ? FLAG_TOSHIBA_DELAY : 0;
 
 	error = NCR5380_init(instance, host_flags);