[PATCH 18/31] swim: Remove redundant RELAX actions

Finn Thain <[email protected]> Thu, 16 Jul 2026 20:02:15 +1000
Newsgroups org.kernel.vger.linux-m68k,org.kernel.vger.linux-block,org.kernel.vger.linux-kernel
Message-ID <46e56724a3d8a9268ff2d086e21e23b6a0b2d97e.1784196135.git.fthain@linux-m68k.org>
Wherever we have a swim_select() or swim_readbit() call there is an
implicit RELAX. That means the caller doesn't have to do it. Remove the
redundant code.

BTW, Inside Macintosh says, "Be sure [...] that CA0 and CA1 are set high
before changing SEL." Hence the RELAX found in swim_select(). The SwimIII
driver in mkLinux also has that. But the swim3.c driver in Linux is odd:
it scatters RELAX actions around as though SEL was not actually under its
control... In anycase, swim.c really does control SEL so there's no need
for that here.

Signed-off-by: Finn Thain <[email protected]>
---
 drivers/block/swim.c | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

diff --git a/drivers/block/swim.c b/drivers/block/swim.c
index 6f93ebaaffb7..b4bf96a788db 100644
--- a/drivers/block/swim.c
+++ b/drivers/block/swim.c
@@ -336,7 +336,6 @@ static inline void swim_motor(struct swim __iomem *base,
 		swim_action(base, MOTOR_ON);
 
 		for (i = 0; i < 2*HZ; i++) {
-			swim_select(base, RELAX);
 			if (swim_readbit(base, MOTOR_ON))
 				break;
 			set_current_state(TASK_INTERRUPTIBLE);
@@ -344,7 +343,7 @@ static inline void swim_motor(struct swim __iomem *base,
 		}
 	} else if (action == OFF) {
 		swim_action(base, MOTOR_OFF);
-		swim_select(base, RELAX);
+		swim_write(base, phase, RELAX);
 	}
 }
 
@@ -355,13 +354,11 @@ static inline void swim_eject(struct swim __iomem *base)
 	swim_action(base, EJECT);
 
 	for (i = 0; i < 2*HZ; i++) {
-		swim_select(base, RELAX);
 		if (!swim_readbit(base, DISK_IN))
 			break;
 		set_current_state(TASK_INTERRUPTIBLE);
 		schedule_timeout(1);
 	}
-	swim_select(base, RELAX);
 }
 
 static inline void swim_head(struct swim __iomem *base, enum head head)
@@ -385,7 +382,6 @@ static inline int swim_step(struct swim __iomem *base)
 		set_current_state(TASK_INTERRUPTIBLE);
 		schedule_timeout(1);
 
-		swim_select(base, RELAX);
 		if (!swim_readbit(base, STEP))
 			return 0;
 	}
@@ -399,8 +395,6 @@ static inline int swim_track00(struct swim __iomem *base)
 	swim_action(base, SEEK_NEGATIVE);
 
 	for (try = 0; try < 100; try++) {
-
-		swim_select(base, RELAX);
 		msleep(3);
 
 		if (swim_readbit(base, TRACK_ZERO))
-- 
2.52.0