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Date:   Tue, 1 Dec 2020 18:05:47 +0100
From:   Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To:     Finn Thain <fthain@telegraphics.com.au>
Cc:     Michael Schmitz <schmitzmic@gmail.com>,
        "James E.J. Bottomley" <jejb@linux.ibm.com>,
        "Martin K. Petersen" <martin.petersen@oracle.com>,
        "Ahmed S. Darwish" <a.darwish@linutronix.de>,
        Thomas Gleixner <tglx@linutronix.de>,
        linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] scsi/NCR5380: Remove in_interrupt() test
Message-ID: <20201201170547.d6ff743eeuh6en6s@linutronix.de>
References: <58cf6feeaf5dae1ee0c78c1b25c00c73de15b087.1606805196.git.fthain@telegraphics.com.au>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
In-Reply-To: <58cf6feeaf5dae1ee0c78c1b25c00c73de15b087.1606805196.git.fthain@telegraphics.com.au>
Precedence: bulk

On 2020-12-01 17:46:36 [+1100], Finn Thain wrote:
> The in_interrupt() macro is deprecated. Also, it's usage in
> NCR5380_poll_politely2() has long been redundant.

So you rely on the assumption that interrupts are always disabled. Hmmm.
You complained about the additional argument and that things may get
wrong with it.
Now that I look at it, I realize that hostdata->poll_loops is used for
the initial poll and the `wait' argument is only used for sleeping. What
about it gets redefined to 0 if sleeping is not possible and != 0 if
sleeping is requested. This results in a few callers passing 0 instead
of HZ (or so) which should make things more obvious.

There is however do_abort(, HZ) and abort does internally "wait * 10" so
it matches the old value.
 
--------------->8------------------

From: "Ahmed S. Darwish" <a.darwish@linutronix.de>
Subject: [PATCH] scsi: NCR5380: Remove in_interrupt() usage.

NCR5380_poll_politely2() uses in_interrupt() to check if it is safe to
sleep.

The usage of in_interrupt() in drivers is phased out and Linus clearly
requested that code which changes behaviour depending on context should
either be separated, or the context be explicitly conveyed in an
argument passed by the caller.

Below is a context analysis of NCR5380_poll_politely2() uppermost
callers:

  - NCR5380_maybe_reset_bus(), task, invoked during device probe.
    -> NCR5380_poll_politely()
    -> do_abort()

  - NCR5380_select(), task, but can only sleep in the "release, then
    re-acquire" regions of the spinlock held by its caller.
    Sleeping invocations (lock released):
    -> NCR5380_poll_politely2()

    Atomic invocations (lock acquired):
    -> NCR5380_reselect()
       -> NCR5380_poll_politely()
       -> do_abort()
       -> NCR5380_transfer_pio()

  - NCR5380_intr(), interrupt handler
    -> NCR5380_dma_complete()
       -> NCR5380_transfer_pio()
	  -> NCR5380_poll_politely()
    -> NCR5380_reselect() (see above)

  - NCR5380_information_transfer(), task, but can only sleep in the
    "release, then re-acquire" regions of the caller-held spinlock.
    Sleeping invocations (lock released):
      - NCR5380_transfer_pio() -> NCR5380_poll_politely()
      - NCR5380_poll_politely()

    Atomic invocations (lock acquired):
      - NCR5380_transfer_dma()
	-> NCR5380_dma_recv_setup()
           => generic_NCR5380_precv() -> NCR5380_poll_politely()
	   => macscsi_pread() -> NCR5380_poll_politely()

	-> NCR5380_dma_send_setup()
 	   => generic_NCR5380_psend -> NCR5380_poll_politely2()
	   => macscsi_pwrite() -> NCR5380_poll_politely()

	-> NCR5380_poll_politely2()
        -> NCR5380_dma_complete()
           -> NCR5380_transfer_pio()
	      -> NCR5380_poll_politely()
      - NCR5380_transfer_pio() -> NCR5380_poll_politely

  - NCR5380_reselect(), atomic, always called with hostdata spinlock
    held.

Use 0 in NCR5380_poll_politely2() delay argument if sleeping is not
possible. Otherwise pass the requested time out in jiffies.

For the mixed ones, trickle-down context from upper layers.

Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
[bigeasy: remove the bool, make decision based on `wait' ]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Finn Thain <fthain@telegraphics.com.au>
Cc: Michael Schmitz <schmitzmic@gmail.com>
Cc: <linux-m68k@lists.linux-m68k.org>
---
 drivers/scsi/NCR5380.c   | 74 ++++++++++++++++++++++------------------
 drivers/scsi/NCR5380.h   |  4 ++-
 drivers/scsi/g_NCR5380.c | 12 +++----
 drivers/scsi/mac_scsi.c  | 10 +++---
 4 files changed, 54 insertions(+), 46 deletions(-)

diff --git a/drivers/scsi/NCR5380.c b/drivers/scsi/NCR5380.c
index d597d7493a627..7b0606d8f529a 100644
--- a/drivers/scsi/NCR5380.c
+++ b/drivers/scsi/NCR5380.c
@@ -132,7 +132,7 @@
 static unsigned int disconnect_mask = ~0;
 module_param(disconnect_mask, int, 0444);
 
-static int do_abort(struct Scsi_Host *);
+static int do_abort(struct Scsi_Host *, unsigned long);
 static void do_reset(struct Scsi_Host *);
 static void bus_reset_cleanup(struct Scsi_Host *);
 
@@ -197,7 +197,7 @@ static inline void set_resid_from_SCp(struct scsi_cmnd *cmd)
  * @reg2: Second 5380 register to poll
  * @bit2: Second bitmask to check
  * @val2: Second expected value
- * @wait: Time-out in jiffies
+ * @wait: Sleep time-out in jiffies, 0 if sleeping is not allowed
  *
  * Polls the chip in a reasonably efficient manner waiting for an
  * event to occur. After a short quick poll we begin to yield the CPU
@@ -223,7 +223,7 @@ static int NCR5380_poll_politely2(struct NCR5380_hostdata *hostdata,
 		cpu_relax();
 	} while (n--);
 
-	if (irqs_disabled() || in_interrupt())
+	if (!wait)
 		return -ETIMEDOUT;
 
 	/* Repeatedly sleep for 1 ms until deadline */
@@ -486,7 +486,7 @@ static int NCR5380_maybe_reset_bus(struct Scsi_Host *instance)
 			break;
 		case 2:
 			shost_printk(KERN_ERR, instance, "bus busy, attempting abort\n");
-			do_abort(instance);
+			do_abort(instance, HZ);
 			break;
 		case 4:
 			shost_printk(KERN_ERR, instance, "bus busy, attempting reset\n");
@@ -822,7 +822,7 @@ static void NCR5380_dma_complete(struct Scsi_Host *instance)
 			if (toPIO > 0) {
 				dsprintk(NDEBUG_DMA, instance,
 				         "Doing %d byte PIO to 0x%p\n", cnt, *data);
-				NCR5380_transfer_pio(instance, &p, &cnt, data);
+				NCR5380_transfer_pio(instance, &p, &cnt, data, 0);
 				*count -= toPIO - cnt;
 			}
 		}
@@ -1189,7 +1189,7 @@ static bool NCR5380_select(struct Scsi_Host *instance, struct scsi_cmnd *cmd)
 		goto out;
 	}
 	if (!hostdata->selecting) {
-		do_abort(instance);
+		do_abort(instance, 0);
 		return false;
 	}
 
@@ -1200,7 +1200,7 @@ static bool NCR5380_select(struct Scsi_Host *instance, struct scsi_cmnd *cmd)
 	len = 1;
 	data = tmp;
 	phase = PHASE_MSGOUT;
-	NCR5380_transfer_pio(instance, &phase, &len, &data);
+	NCR5380_transfer_pio(instance, &phase, &len, &data, 0);
 	if (len) {
 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
 		cmd->result = DID_ERROR << 16;
@@ -1238,7 +1238,8 @@ static bool NCR5380_select(struct Scsi_Host *instance, struct scsi_cmnd *cmd)
  *
  * Inputs : instance - instance of driver, *phase - pointer to
  * what phase is expected, *count - pointer to number of
- * bytes to transfer, **data - pointer to data pointer.
+ * bytes to transfer, **data - pointer to data pointer,
+ * wait - sleep time-out in jiffies, 0 if sleeping is now allowed.
  *
  * Returns : -1 when different phase is entered without transferring
  * maximum number of bytes, 0 if all bytes are transferred or exit
@@ -1257,7 +1258,7 @@ static bool NCR5380_select(struct Scsi_Host *instance, struct scsi_cmnd *cmd)
 
 static int NCR5380_transfer_pio(struct Scsi_Host *instance,
 				unsigned char *phase, int *count,
-				unsigned char **data)
+				unsigned char **data, unsigned long wait)
 {
 	struct NCR5380_hostdata *hostdata = shost_priv(instance);
 	unsigned char p = *phase, tmp;
@@ -1278,7 +1279,8 @@ static int NCR5380_transfer_pio(struct Scsi_Host *instance,
 		 * valid
 		 */
 
-		if (NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ, HZ) < 0)
+		if (NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ,
+					  wait) < 0)
 			break;
 
 		dsprintk(NDEBUG_HANDSHAKE, instance, "REQ asserted\n");
@@ -1324,7 +1326,7 @@ static int NCR5380_transfer_pio(struct Scsi_Host *instance,
 		}
 
 		if (NCR5380_poll_politely(hostdata,
-		                          STATUS_REG, SR_REQ, 0, 5 * HZ) < 0)
+		                          STATUS_REG, SR_REQ, 0, wait * 5) < 0)
 			break;
 
 		dsprintk(NDEBUG_HANDSHAKE, instance, "REQ negated, handshake complete\n");
@@ -1399,11 +1401,12 @@ static void do_reset(struct Scsi_Host *instance)
  * do_abort - abort the currently established nexus by going to
  * MESSAGE OUT phase and sending an ABORT message.
  * @instance: relevant scsi host instance
+ * @wait: Sleep time-out in jiffies.
  *
  * Returns 0 on success, negative error code on failure.
  */
 
-static int do_abort(struct Scsi_Host *instance)
+static int do_abort(struct Scsi_Host *instance, unsigned long wait)
 {
 	struct NCR5380_hostdata *hostdata = shost_priv(instance);
 	unsigned char *msgptr, phase, tmp;
@@ -1423,7 +1426,8 @@ static int do_abort(struct Scsi_Host *instance)
 	 * the target sees, so we just handshake.
 	 */
 
-	rc = NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ, 10 * HZ);
+	rc = NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ,
+				   wait * 10);
 	if (rc < 0)
 		goto out;
 
@@ -1434,7 +1438,8 @@ static int do_abort(struct Scsi_Host *instance)
 	if (tmp != PHASE_MSGOUT) {
 		NCR5380_write(INITIATOR_COMMAND_REG,
 		              ICR_BASE | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
-		rc = NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, 0, 3 * HZ);
+		rc = NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, 0,
+					   wait * 3);
 		if (rc < 0)
 			goto out;
 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
@@ -1444,7 +1449,7 @@ static int do_abort(struct Scsi_Host *instance)
 	msgptr = &tmp;
 	len = 1;
 	phase = PHASE_MSGOUT;
-	NCR5380_transfer_pio(instance, &phase, &len, &msgptr);
+	NCR5380_transfer_pio(instance, &phase, &len, &msgptr, wait);
 	if (len)
 		rc = -ENXIO;
 
@@ -1623,12 +1628,12 @@ static int NCR5380_transfer_dma(struct Scsi_Host *instance,
 			 */
 
 			if (NCR5380_poll_politely(hostdata, BUS_AND_STATUS_REG,
-			                          BASR_DRQ, BASR_DRQ, HZ) < 0) {
+			                          BASR_DRQ, BASR_DRQ, 0) < 0) {
 				result = -1;
 				shost_printk(KERN_ERR, instance, "PDMA read: DRQ timeout\n");
 			}
 			if (NCR5380_poll_politely(hostdata, STATUS_REG,
-			                          SR_REQ, 0, HZ) < 0) {
+			                          SR_REQ, 0, 0) < 0) {
 				result = -1;
 				shost_printk(KERN_ERR, instance, "PDMA read: !REQ timeout\n");
 			}
@@ -1640,7 +1645,7 @@ static int NCR5380_transfer_dma(struct Scsi_Host *instance,
 			 */
 			if (NCR5380_poll_politely2(hostdata,
 			     BUS_AND_STATUS_REG, BASR_DRQ, BASR_DRQ,
-			     BUS_AND_STATUS_REG, BASR_PHASE_MATCH, 0, HZ) < 0) {
+			     BUS_AND_STATUS_REG, BASR_PHASE_MATCH, 0, 0) < 0) {
 				result = -1;
 				shost_printk(KERN_ERR, instance, "PDMA write: DRQ and phase timeout\n");
 			}
@@ -1737,7 +1742,7 @@ static void NCR5380_information_transfer(struct Scsi_Host *instance)
 #if (NDEBUG & NDEBUG_NO_DATAOUT)
 				shost_printk(KERN_DEBUG, instance, "NDEBUG_NO_DATAOUT set, attempted DATAOUT aborted\n");
 				sink = 1;
-				do_abort(instance);
+				do_abort(instance, 0);
 				cmd->result = DID_ERROR << 16;
 				complete_cmd(instance, cmd);
 				hostdata->connected = NULL;
@@ -1793,7 +1798,8 @@ static void NCR5380_information_transfer(struct Scsi_Host *instance)
 							   NCR5380_PIO_CHUNK_SIZE);
 					len = transfersize;
 					NCR5380_transfer_pio(instance, &phase, &len,
-					                     (unsigned char **)&cmd->SCp.ptr);
+					                     (unsigned char **)&cmd->SCp.ptr,
+							     0);
 					cmd->SCp.this_residual -= transfersize - len;
 				}
 #ifdef CONFIG_SUN3
@@ -1804,7 +1810,7 @@ static void NCR5380_information_transfer(struct Scsi_Host *instance)
 			case PHASE_MSGIN:
 				len = 1;
 				data = &tmp;
-				NCR5380_transfer_pio(instance, &phase, &len, &data);
+				NCR5380_transfer_pio(instance, &phase, &len, &data, 0);
 				cmd->SCp.Message = tmp;
 
 				switch (tmp) {
@@ -1910,7 +1916,7 @@ static void NCR5380_information_transfer(struct Scsi_Host *instance)
 					len = 2;
 					data = extended_msg + 1;
 					phase = PHASE_MSGIN;
-					NCR5380_transfer_pio(instance, &phase, &len, &data);
+					NCR5380_transfer_pio(instance, &phase, &len, &data, HZ);
 					dsprintk(NDEBUG_EXTENDED, instance, "length %d, code 0x%02x\n",
 					         (int)extended_msg[1],
 					         (int)extended_msg[2]);
@@ -1923,7 +1929,7 @@ static void NCR5380_information_transfer(struct Scsi_Host *instance)
 						data = extended_msg + 3;
 						phase = PHASE_MSGIN;
 
-						NCR5380_transfer_pio(instance, &phase, &len, &data);
+						NCR5380_transfer_pio(instance, &phase, &len, &data, HZ);
 						dsprintk(NDEBUG_EXTENDED, instance, "message received, residual %d\n",
 						         len);
 
@@ -1970,7 +1976,7 @@ static void NCR5380_information_transfer(struct Scsi_Host *instance)
 				len = 1;
 				data = &msgout;
 				hostdata->last_message = msgout;
-				NCR5380_transfer_pio(instance, &phase, &len, &data);
+				NCR5380_transfer_pio(instance, &phase, &len, &data, 0);
 				if (msgout == ABORT) {
 					hostdata->connected = NULL;
 					hostdata->busy[scmd_id(cmd)] &= ~(1 << cmd->device->lun);
@@ -1988,12 +1994,12 @@ static void NCR5380_information_transfer(struct Scsi_Host *instance)
 				 * PSEUDO-DMA architecture we should probably
 				 * use the dma transfer function.
 				 */
-				NCR5380_transfer_pio(instance, &phase, &len, &data);
+				NCR5380_transfer_pio(instance, &phase, &len, &data, 0);
 				break;
 			case PHASE_STATIN:
 				len = 1;
 				data = &tmp;
-				NCR5380_transfer_pio(instance, &phase, &len, &data);
+				NCR5380_transfer_pio(instance, &phase, &len, &data, 0);
 				cmd->SCp.Status = tmp;
 				break;
 			default:
@@ -2052,7 +2058,7 @@ static void NCR5380_reselect(struct Scsi_Host *instance)
 
 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY);
 	if (NCR5380_poll_politely(hostdata,
-	                          STATUS_REG, SR_SEL, 0, 2 * HZ) < 0) {
+	                          STATUS_REG, SR_SEL, 0, 0) < 0) {
 		shost_printk(KERN_ERR, instance, "reselect: !SEL timeout\n");
 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
 		return;
@@ -2064,12 +2070,12 @@ static void NCR5380_reselect(struct Scsi_Host *instance)
 	 */
 
 	if (NCR5380_poll_politely(hostdata,
-	                          STATUS_REG, SR_REQ, SR_REQ, 2 * HZ) < 0) {
+	                          STATUS_REG, SR_REQ, SR_REQ, 0) < 0) {
 		if ((NCR5380_read(STATUS_REG) & (SR_BSY | SR_SEL)) == 0)
 			/* BUS FREE phase */
 			return;
 		shost_printk(KERN_ERR, instance, "reselect: REQ timeout\n");
-		do_abort(instance);
+		do_abort(instance, 0);
 		return;
 	}
 
@@ -2085,10 +2091,10 @@ static void NCR5380_reselect(struct Scsi_Host *instance)
 		unsigned char *data = msg;
 		unsigned char phase = PHASE_MSGIN;
 
-		NCR5380_transfer_pio(instance, &phase, &len, &data);
+		NCR5380_transfer_pio(instance, &phase, &len, &data, 0);
 
 		if (len) {
-			do_abort(instance);
+			do_abort(instance, 0);
 			return;
 		}
 	}
@@ -2098,7 +2104,7 @@ static void NCR5380_reselect(struct Scsi_Host *instance)
 		shost_printk(KERN_ERR, instance, "expecting IDENTIFY message, got ");
 		spi_print_msg(msg);
 		printk("\n");
-		do_abort(instance);
+		do_abort(instance, 0);
 		return;
 	}
 	lun = msg[0] & 0x07;
@@ -2138,7 +2144,7 @@ static void NCR5380_reselect(struct Scsi_Host *instance)
 		 * Since we have an established nexus that we can't do anything
 		 * with, we must abort it.
 		 */
-		if (do_abort(instance) == 0)
+		if (do_abort(instance, 0) == 0)
 			hostdata->busy[target] &= ~(1 << lun);
 		return;
 	}
@@ -2285,7 +2291,7 @@ static int NCR5380_abort(struct scsi_cmnd *cmd)
 		dsprintk(NDEBUG_ABORT, instance, "abort: cmd %p is connected\n", cmd);
 		hostdata->connected = NULL;
 		hostdata->dma_len = 0;
-		if (do_abort(instance) < 0) {
+		if (do_abort(instance, 0) < 0) {
 			set_host_byte(cmd, DID_ERROR);
 			complete_cmd(instance, cmd);
 			result = FAILED;
diff --git a/drivers/scsi/NCR5380.h b/drivers/scsi/NCR5380.h
index 5935fd6d1a058..578983e328d19 100644
--- a/drivers/scsi/NCR5380.h
+++ b/drivers/scsi/NCR5380.h
@@ -277,7 +277,9 @@ static const char *NCR5380_info(struct Scsi_Host *instance);
 static void NCR5380_reselect(struct Scsi_Host *instance);
 static bool NCR5380_select(struct Scsi_Host *, struct scsi_cmnd *);
 static int NCR5380_transfer_dma(struct Scsi_Host *instance, unsigned char *phase, int *count, unsigned char **data);
-static int NCR5380_transfer_pio(struct Scsi_Host *instance, unsigned char *phase, int *count, unsigned char **data);
+static int NCR5380_transfer_pio(struct Scsi_Host *instance, unsigned char *phase,
+				int *count, unsigned char **data,
+				unsigned long wait);
 static int NCR5380_poll_politely2(struct NCR5380_hostdata *,
                                   unsigned int, u8, u8,
                                   unsigned int, u8, u8, unsigned long);
diff --git a/drivers/scsi/g_NCR5380.c b/drivers/scsi/g_NCR5380.c
index 29e4cdcade720..2df2f38a9b122 100644
--- a/drivers/scsi/g_NCR5380.c
+++ b/drivers/scsi/g_NCR5380.c
@@ -529,14 +529,14 @@ static inline int generic_NCR5380_precv(struct NCR5380_hostdata *hostdata,
 		if (start == len - 128) {
 			/* Ignore End of DMA interrupt for the final buffer */
 			if (NCR5380_poll_politely(hostdata, hostdata->c400_ctl_status,
-			                          CSR_HOST_BUF_NOT_RDY, 0, HZ / 64) < 0)
+			                          CSR_HOST_BUF_NOT_RDY, 0, 0) < 0)
 				break;
 		} else {
 			if (NCR5380_poll_politely2(hostdata, hostdata->c400_ctl_status,
 			                           CSR_HOST_BUF_NOT_RDY, 0,
 			                           hostdata->c400_ctl_status,
 			                           CSR_GATED_53C80_IRQ,
-			                           CSR_GATED_53C80_IRQ, HZ / 64) < 0 ||
+			                           CSR_GATED_53C80_IRQ, 0) < 0 ||
 			    NCR5380_read(hostdata->c400_ctl_status) & CSR_HOST_BUF_NOT_RDY)
 				break;
 		}
@@ -565,7 +565,7 @@ static inline int generic_NCR5380_precv(struct NCR5380_hostdata *hostdata,
 	if (residual == 0 && NCR5380_poll_politely(hostdata, BUS_AND_STATUS_REG,
 	                                           BASR_END_DMA_TRANSFER,
 	                                           BASR_END_DMA_TRANSFER,
-	                                           HZ / 64) < 0)
+						   0) < 0)
 		scmd_printk(KERN_ERR, hostdata->connected, "%s: End of DMA timeout\n",
 		            __func__);
 
@@ -597,7 +597,7 @@ static inline int generic_NCR5380_psend(struct NCR5380_hostdata *hostdata,
 		                           CSR_HOST_BUF_NOT_RDY, 0,
 		                           hostdata->c400_ctl_status,
 		                           CSR_GATED_53C80_IRQ,
-		                           CSR_GATED_53C80_IRQ, HZ / 64) < 0 ||
+		                           CSR_GATED_53C80_IRQ, 0) < 0 ||
 		    NCR5380_read(hostdata->c400_ctl_status) & CSR_HOST_BUF_NOT_RDY) {
 			/* Both 128 B buffers are in use */
 			if (start >= 128)
@@ -644,13 +644,13 @@ static inline int generic_NCR5380_psend(struct NCR5380_hostdata *hostdata,
 	if (residual == 0) {
 		if (NCR5380_poll_politely(hostdata, TARGET_COMMAND_REG,
 		                          TCR_LAST_BYTE_SENT, TCR_LAST_BYTE_SENT,
-		                          HZ / 64) < 0)
+					  0) < 0)
 			scmd_printk(KERN_ERR, hostdata->connected,
 			            "%s: Last Byte Sent timeout\n", __func__);
 
 		if (NCR5380_poll_politely(hostdata, BUS_AND_STATUS_REG,
 		                          BASR_END_DMA_TRANSFER, BASR_END_DMA_TRANSFER,
-		                          HZ / 64) < 0)
+					  0) < 0)
 			scmd_printk(KERN_ERR, hostdata->connected, "%s: End of DMA timeout\n",
 			            __func__);
 	}
diff --git a/drivers/scsi/mac_scsi.c b/drivers/scsi/mac_scsi.c
index b5dde9d0d0545..5c808fbc6ce2c 100644
--- a/drivers/scsi/mac_scsi.c
+++ b/drivers/scsi/mac_scsi.c
@@ -285,7 +285,7 @@ static inline int macscsi_pread(struct NCR5380_hostdata *hostdata,
 
 	while (!NCR5380_poll_politely(hostdata, BUS_AND_STATUS_REG,
 	                              BASR_DRQ | BASR_PHASE_MATCH,
-	                              BASR_DRQ | BASR_PHASE_MATCH, HZ / 64)) {
+	                              BASR_DRQ | BASR_PHASE_MATCH, 0)) {
 		int bytes;
 
 		if (macintosh_config->ident == MAC_MODEL_IIFX)
@@ -304,7 +304,7 @@ static inline int macscsi_pread(struct NCR5380_hostdata *hostdata,
 
 		if (NCR5380_poll_politely2(hostdata, STATUS_REG, SR_REQ, SR_REQ,
 		                           BUS_AND_STATUS_REG, BASR_ACK,
-		                           BASR_ACK, HZ / 64) < 0)
+		                           BASR_ACK, 0) < 0)
 			scmd_printk(KERN_DEBUG, hostdata->connected,
 			            "%s: !REQ and !ACK\n", __func__);
 		if (!(NCR5380_read(BUS_AND_STATUS_REG) & BASR_PHASE_MATCH))
@@ -344,7 +344,7 @@ static inline int macscsi_pwrite(struct NCR5380_hostdata *hostdata,
 
 	while (!NCR5380_poll_politely(hostdata, BUS_AND_STATUS_REG,
 	                              BASR_DRQ | BASR_PHASE_MATCH,
-	                              BASR_DRQ | BASR_PHASE_MATCH, HZ / 64)) {
+	                              BASR_DRQ | BASR_PHASE_MATCH, 0)) {
 		int bytes;
 
 		if (macintosh_config->ident == MAC_MODEL_IIFX)
@@ -362,7 +362,7 @@ static inline int macscsi_pwrite(struct NCR5380_hostdata *hostdata,
 			if (NCR5380_poll_politely(hostdata, TARGET_COMMAND_REG,
 			                          TCR_LAST_BYTE_SENT,
 			                          TCR_LAST_BYTE_SENT,
-			                          HZ / 64) < 0) {
+			                          0) < 0) {
 				scmd_printk(KERN_ERR, hostdata->connected,
 				            "%s: Last Byte Sent timeout\n", __func__);
 				result = -1;
@@ -372,7 +372,7 @@ static inline int macscsi_pwrite(struct NCR5380_hostdata *hostdata,
 
 		if (NCR5380_poll_politely2(hostdata, STATUS_REG, SR_REQ, SR_REQ,
 		                           BUS_AND_STATUS_REG, BASR_ACK,
-		                           BASR_ACK, HZ / 64) < 0)
+		                           BASR_ACK, 0) < 0)
 			scmd_printk(KERN_DEBUG, hostdata->connected,
 			            "%s: !REQ and !ACK\n", __func__);
 		if (!(NCR5380_read(BUS_AND_STATUS_REG) & BASR_PHASE_MATCH))
-- 
2.29.2