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From: Finn Thain <fthain@linux-m68k.org>
To: Jens Axboe <axboe@kernel.dk>, Laurent Vivier <laurent@vivier.eu>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>,
	Joshua Thompson <funaho@jurai.org>,
	linux-block@vger.kernel.org, linux-m68k@lists.linux-m68k.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH v3 19/33] swim: Remove redundant RELAX actions
Date: Fri, 04 Sep 2026 19:26:36 +1000	[thread overview]
Message-ID: <08ab67c2780c9107b87a1ece8b5f9cb54a8cea70.1788513997.git.fthain@linux-m68k.org> (raw)
In-Reply-To: <cover.1788513996.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.

Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Finn Thain <fthain@linux-m68k.org>
---
 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 c3fbcf377d1f..ea4663945505 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 | PHASE_PIN_DIR);
 	}
 }
 
@@ -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


  parent reply	other threads:[~2026-09-04  9:34 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-09-04  9:26 [PATCH v3 00/33] block/swim: Fixes and improvements Finn Thain
2026-09-04  9:26 ` [PATCH v3 06/33] swim: Configure parameter memory Finn Thain
2026-09-04  9:26 ` [PATCH v3 14/33] swim: Check for CRC errors Finn Thain
2026-09-04  9:26 ` [PATCH v3 11/33] swim: Add track zero recalibration delay Finn Thain
2026-09-04  9:26 ` [PATCH v3 27/33] swim: Move swd initialization Finn Thain
2026-09-04  9:26 ` [PATCH v3 08/33] swim: Enable clock divider only where appropriate Finn Thain
2026-09-04  9:26 ` [PATCH v3 02/33] swim: Select appropriate drive once only Finn Thain
2026-09-04  9:26 ` [PATCH v3 29/33] swim: Remove unused macro definitions Finn Thain
2026-09-04  9:26 ` [PATCH v3 22/33] swim: Revisit delays Finn Thain
2026-09-04  9:26 ` [PATCH v3 30/33] swim: Clean up whitespace Finn Thain
2026-09-04  9:26 ` [PATCH v3 10/33] swim: Recalibrate when drive is probed Finn Thain
2026-09-04  9:26 ` [PATCH v3 07/33] swim: Refactor SWIM setup Finn Thain
2026-09-04  9:26 ` [PATCH v3 23/33] swim: Remove pointless mode0 register write Finn Thain
2026-09-04  9:26 ` [PATCH v3 15/33] swim: Check error register during sector read Finn Thain
2026-09-04  9:26 ` [PATCH v3 16/33] swim: Don't use the mark register to read data Finn Thain
2026-09-04  9:26 ` [PATCH v3 05/33] swim: Perform ISM/IWM mode switching according to specs Finn Thain
2026-09-04  9:26 ` [PATCH v3 01/33] swim: Assert strobe with stable outputs Finn Thain
2026-09-04  9:26 ` [PATCH v3 21/33] swim: Check drive ready bit Finn Thain
2026-09-04  9:26 ` [PATCH v3 25/33] swim: Don't search beyond the first data mark Finn Thain
2026-09-04  9:26 ` [PATCH v3 12/33] swim: Handle FIFO timeout error Finn Thain
2026-09-04  9:26 ` [PATCH v3 20/33] swim: Deduplicate polling loops Finn Thain
2026-09-04  9:26 ` [PATCH v3 17/33] swim: Fix buffer overflow Finn Thain
2026-09-04  9:26 ` Finn Thain [this message]
2026-09-04  9:26 ` [PATCH v3 32/33] swim: Define symbols for constants Finn Thain
2026-09-04  9:26 ` [PATCH v3 31/33] swim: Define macros " Finn Thain
2026-09-04  9:26 ` [PATCH v3 33/33] swim: Unexport global symbols Finn Thain
2026-09-04  9:26 ` [PATCH v3 28/33] swim: Add some helpful references Finn Thain
2026-09-04  9:26 ` [PATCH v3 09/33] swim: Don't start motor until medium is present Finn Thain
2026-09-04  9:26 ` [PATCH v3 03/33] swim: Enable the drive when probing Finn Thain
2026-09-04  9:26 ` [PATCH v3 04/33] swim: Don't disable drive after every sector Finn Thain
2026-09-04  9:26 ` [PATCH v3 18/33] swim: Convert to blocking queue Finn Thain
2026-09-04  9:26 ` [PATCH v3 26/33] swim: Remove pointless specifiers Finn Thain
2026-09-04  9:26 ` [PATCH v3 24/33] swim: Don't needlessly re-read sectors Finn Thain
2026-09-04  9:26 ` [PATCH v3 13/33] swim: Simplify return value initialization Finn Thain
2026-09-23  8:26 ` [PATCH v3 00/33] block/swim: Fixes and improvements Stanley J. Johnson
2026-09-23 11:15 ` Jens Axboe

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