[PATCH 03/10] NCR5380: Have NCR5380_select() return a bool
From: Finn Thain
Date: Wed Sep 26 2018 - 21:28:07 EST
The return value is taken to mean "retry" or "don't retry". Change it to
bool to improve readability. Fix related comments. No functional change.
Tested-by: Michael Schmitz <schmitzmic@xxxxxxxxx>
Signed-off-by: Finn Thain <fthain@xxxxxxxxxxxxxxxxxxx>
---
drivers/scsi/NCR5380.c | 46 +++++++++++++++++++++-------------------------
drivers/scsi/NCR5380.h | 2 +-
2 files changed, 22 insertions(+), 26 deletions(-)
diff --git a/drivers/scsi/NCR5380.c b/drivers/scsi/NCR5380.c
index c6d10780febe..7be1ba2b9e4e 100644
--- a/drivers/scsi/NCR5380.c
+++ b/drivers/scsi/NCR5380.c
@@ -902,20 +902,16 @@ static irqreturn_t __maybe_unused NCR5380_intr(int irq, void *dev_id)
return IRQ_RETVAL(handled);
}
-/*
- * Function : int NCR5380_select(struct Scsi_Host *instance,
- * struct scsi_cmnd *cmd)
- *
- * Purpose : establishes I_T_L or I_T_L_Q nexus for new or existing command,
- * including ARBITRATION, SELECTION, and initial message out for
- * IDENTIFY and queue messages.
+/**
+ * NCR5380_select - attempt arbitration and selection for a given command
+ * @instance: the Scsi_Host instance
+ * @cmd: the scsi_cmnd to execute
*
- * Inputs : instance - instantiation of the 5380 driver on which this
- * target lives, cmd - SCSI command to execute.
+ * This routine establishes an I_T_L nexus for a SCSI command. This involves
+ * ARBITRATION, SELECTION and MESSAGE OUT phases and an IDENTIFY message.
*
- * Returns cmd if selection failed but should be retried,
- * NULL if selection failed and should not be retried, or
- * NULL if selection succeeded (hostdata->connected == cmd).
+ * Returns true if the operation should be retried.
+ * Returns false if it should not be retried.
*
* Side effects :
* If bus busy, arbitration failed, etc, NCR5380_select() will exit
@@ -923,16 +919,15 @@ static irqreturn_t __maybe_unused NCR5380_intr(int irq, void *dev_id)
* SELECT_ENABLE will be set appropriately, the NCR5380
* will cease to drive any SCSI bus signals.
*
- * If successful : I_T_L or I_T_L_Q nexus will be established,
- * instance->connected will be set to cmd.
+ * If successful : the I_T_L nexus will be established, and
+ * hostdata->connected will be set to cmd.
* SELECT interrupt will be disabled.
*
* If failed (no target) : cmd->scsi_done() will be called, and the
* cmd->result host byte set to DID_BAD_TARGET.
*/
-static struct scsi_cmnd *NCR5380_select(struct Scsi_Host *instance,
- struct scsi_cmnd *cmd)
+static bool NCR5380_select(struct Scsi_Host *instance, struct scsi_cmnd *cmd)
__releases(&hostdata->lock) __acquires(&hostdata->lock)
{
struct NCR5380_hostdata *hostdata = shost_priv(instance);
@@ -940,6 +935,7 @@ static struct scsi_cmnd *NCR5380_select(struct Scsi_Host *instance,
unsigned char *data;
int len;
int err;
+ bool ret = true;
NCR5380_dprint(NDEBUG_ARBITRATION, instance);
dsprintk(NDEBUG_ARBITRATION, instance, "starting arbitration, id = %d\n",
@@ -948,7 +944,7 @@ static struct scsi_cmnd *NCR5380_select(struct Scsi_Host *instance,
/*
* Arbitration and selection phases are slow and involve dropping the
* lock, so we have to watch out for EH. An exception handler may
- * change 'selecting' to NULL. This function will then return NULL
+ * change 'selecting' to NULL. This function will then return false
* so that the caller will forget about 'cmd'. (During information
* transfer phases, EH may change 'connected' to NULL.)
*/
@@ -984,7 +980,7 @@ static struct scsi_cmnd *NCR5380_select(struct Scsi_Host *instance,
if (!hostdata->selecting) {
/* Command was aborted */
NCR5380_write(MODE_REG, MR_BASE);
- return NULL;
+ return false;
}
if (err < 0) {
NCR5380_write(MODE_REG, MR_BASE);
@@ -1033,7 +1029,7 @@ static struct scsi_cmnd *NCR5380_select(struct Scsi_Host *instance,
if (!hostdata->selecting) {
NCR5380_write(MODE_REG, MR_BASE);
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
- return NULL;
+ return false;
}
dsprintk(NDEBUG_ARBITRATION, instance, "won arbitration\n");
@@ -1119,13 +1115,13 @@ static struct scsi_cmnd *NCR5380_select(struct Scsi_Host *instance,
/* Can't touch cmd if it has been reclaimed by the scsi ML */
if (!hostdata->selecting)
- return NULL;
+ return false;
cmd->result = DID_BAD_TARGET << 16;
complete_cmd(instance, cmd);
dsprintk(NDEBUG_SELECTION, instance,
"target did not respond within 250ms\n");
- cmd = NULL;
+ ret = false;
goto out;
}
@@ -1158,7 +1154,7 @@ static struct scsi_cmnd *NCR5380_select(struct Scsi_Host *instance,
}
if (!hostdata->selecting) {
do_abort(instance);
- return NULL;
+ return false;
}
dsprintk(NDEBUG_SELECTION, instance, "target %d selected, going into MESSAGE OUT phase.\n",
@@ -1174,7 +1170,7 @@ static struct scsi_cmnd *NCR5380_select(struct Scsi_Host *instance,
cmd->result = DID_ERROR << 16;
complete_cmd(instance, cmd);
dsprintk(NDEBUG_SELECTION, instance, "IDENTIFY message transfer failed\n");
- cmd = NULL;
+ ret = false;
goto out;
}
@@ -1189,13 +1185,13 @@ static struct scsi_cmnd *NCR5380_select(struct Scsi_Host *instance,
initialize_SCp(cmd);
- cmd = NULL;
+ ret = false;
out:
if (!hostdata->selecting)
return NULL;
hostdata->selecting = NULL;
- return cmd;
+ return ret;
}
/*
diff --git a/drivers/scsi/NCR5380.h b/drivers/scsi/NCR5380.h
index 31096a0b0fdd..efca509b92b0 100644
--- a/drivers/scsi/NCR5380.h
+++ b/drivers/scsi/NCR5380.h
@@ -275,7 +275,7 @@ static irqreturn_t NCR5380_intr(int irq, void *dev_id);
static void NCR5380_main(struct work_struct *work);
static const char *NCR5380_info(struct Scsi_Host *instance);
static void NCR5380_reselect(struct Scsi_Host *instance);
-static struct scsi_cmnd *NCR5380_select(struct Scsi_Host *, struct scsi_cmnd *);
+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_poll_politely2(struct NCR5380_hostdata *,
--
2.16.4