[PATCH 15/31] swim: Don't use the mark register to read data

[Finn Thain]

If an unexpected mark byte were to be read from the data register, an
error would be flagged. But no error gets flagged when such a byte is
read from the mark register, which is misleading. Always use the data
register except when a mark byte is expected.

Fixes: 8852ecd97488 ("m68k: mac - Add SWIM floppy support")
Signed-off-by: Finn Thain <fthain@xxxxxxxxxxxxxx>
---
 drivers/block/swim_asm.S | 21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/drivers/block/swim_asm.S b/drivers/block/swim_asm.S
index 1d394ee930d6..5caeba3a75d8 100644
--- a/drivers/block/swim_asm.S
+++ b/drivers/block/swim_asm.S
@@ -47,11 +47,11 @@
 	.global swim_read_sector_header
 swim_read_sector_header:
 	link	%a6, #0
-	moveml	%d1-%d5/%a0-%a4,%sp@-
+	moveml	%d1-%d5/%a0-%a5,%sp@-
 	movel	%a6@(0x0c), %a4
 	moveq	#-1, %d0
 	bsr	mfm_read_addrmark
-	moveml	%sp@+, %d1-%d5/%a0-%a4
+	moveml	%sp@+, %d1-%d5/%a0-%a5
 	unlk	%a6
 	rts
 
@@ -63,6 +63,7 @@ sector_data_mark:
 mfm_read_addrmark:
 	movel	%a6@(0x08), %a3
 	lea	%a3@(read_handshake), %a2
+	lea	%a3@(read_data), %a5
 	lea	%a3@(read_mark), %a3
 	movew	#seek_time, %d2
 
@@ -93,7 +94,7 @@ amark0:	tstb	%a2@
 	dbmi	%d2, amark0
 	bpl	signal_nonyb
 
-	moveb	%a3@, %a4@(o_track)
+	moveb	%a5@, %a4@(o_track)
 
 	moveq	#max_retry, %d2
 
@@ -101,7 +102,7 @@ amark1:	tstb	%a2@
 	dbmi	%d2, amark1
 	bpl	signal_nonyb
 
-	moveb	%a3@, %a4@(o_side)
+	moveb	%a5@, %a4@(o_side)
 
 	moveq	#max_retry, %d2
 
@@ -109,7 +110,7 @@ amark2:	tstb	%a2@
 	dbmi	%d2, amark2
 	bpl	signal_nonyb
 
-	moveb	%a3@, %a4@(o_sector)
+	moveb	%a5@, %a4@(o_sector)
 
 	moveq	#max_retry, %d2
 
@@ -117,7 +118,7 @@ amark3:	tstb	%a2@
 	dbmi	%d2, amark3
 	bpl	signal_nonyb
 
-	moveb	%a3@, %a4@(o_size)
+	moveb	%a5@, %a4@(o_size)
 
 	moveq	#max_retry, %d2
 
@@ -125,7 +126,7 @@ crc0:	tstb	%a2@
 	dbmi	%d2, crc0
 	bpl	signal_nonyb
 
-	moveb	%a3@, %a4@(o_crc0)
+	moveb	%a5@, %a4@(o_crc0)
 
 	moveq	#max_retry, %d2
 
@@ -133,7 +134,7 @@ crc1:	moveb	%a2@, %d5
 	dbmi	%d2, crc1
 	bpl	signal_nonyb
 
-	moveb	%a3@, %a4@(o_crc1)
+	moveb	%a5@, %a4@(o_crc1)
 
 	andb	#.Lhr_crc_error, %d5
 	bne	signal_nonyb
@@ -211,7 +212,7 @@ data_crc0:
 	dbmi	%d2, data_crc0
 	bpl	data_exit
 
-	moveb	%a3@, %d2
+	moveb	%a5@, %d2
 
 	moveq	#max_retry, %d2
 
@@ -221,7 +222,7 @@ data_crc1:
 	dbmi	%d2, data_crc1
 	bpl	data_exit
 
-	moveb	%a3@, %d2
+	moveb	%a5@, %d2
 
 	andb	#.Lhr_crc_error, %d5
 	bne	data_exit
-- 
2.52.0