atari_NCR5380: Use arbitration timeout

Allow target selection to fail with a timeout instead of waiting in
infinite loops. This gets rid of the unused NCR_TIMEOUT macro, it is more
defensive and has proved helpful in debugging.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/NCR5380.c b/drivers/scsi/NCR5380.c
index 973ea5189dd45b309b11829bf0b0cade193f3a63..97975cb273374f7da03be19d744c43321c77d2a3 100644 (file)
--- a/drivers/scsi/NCR5380.c
+++ b/drivers/scsi/NCR5380.c
@@ -1083,6 +1083,7 @@ static int NCR5380_select(struct Scsi_Host *instance, struct scsi_cmnd *cmd)
        unsigned char *data;
        int len;
        int err;
+       unsigned long timeout;
 
        NCR5380_dprint(NDEBUG_ARBITRATION, instance);
        dprintk(NDEBUG_ARBITRATION, "scsi%d : starting arbitration, id = %d\n", instance->host_no, instance->this_id);
@@ -1101,28 +1102,31 @@ static int NCR5380_select(struct Scsi_Host *instance, struct scsi_cmnd *cmd)
        NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
        NCR5380_write(MODE_REG, MR_ARBITRATE);
 
+       /* The chip now waits for BUS FREE phase. Then after the 800 ns
+        * Bus Free Delay, arbitration will begin.
+        */
 
-       /* We can be relaxed here, interrupts are on, we are
-          in workqueue context, the birds are singing in the trees */
        spin_unlock_irq(instance->host_lock);
-       err = NCR5380_poll_politely(instance, INITIATOR_COMMAND_REG, ICR_ARBITRATION_PROGRESS, ICR_ARBITRATION_PROGRESS, 5*HZ);
-       spin_lock_irq(instance->host_lock);
-       if (err < 0) {
-               printk(KERN_DEBUG "scsi: arbitration timeout at %d\n", __LINE__);
-               NCR5380_write(MODE_REG, MR_BASE);
-               NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
-               return -1;
+       timeout = jiffies + HZ;
+       while (1) {
+               if (time_is_before_jiffies(timeout)) {
+                       NCR5380_write(MODE_REG, MR_BASE);
+                       shost_printk(KERN_ERR, instance,
+                                    "select: arbitration timeout\n");
+                       spin_lock_irq(instance->host_lock);
+                       return -1;
+               }
+               spin_lock_irq(instance->host_lock);
+               if (!(NCR5380_read(MODE_REG) & MR_ARBITRATE)) {
+                       /* Reselection interrupt */
+                       return -1;
+               }
+               if (NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_PROGRESS)
+                       break;
+               spin_unlock_irq(instance->host_lock);
        }
 
-       dprintk(NDEBUG_ARBITRATION, "scsi%d : arbitration complete\n", instance->host_no);
-
-       /* 
-        * The arbitration delay is 2.2us, but this is a minimum and there is 
-        * no maximum so we can safely sleep for ceil(2.2) usecs to accommodate
-        * the integral nature of udelay().
-        *
-        */
-
+       /* The SCSI-2 arbitration delay is 2.4 us */
        udelay(3);
 
        /* Check for lost arbitration */
@@ -1270,9 +1274,9 @@ static int NCR5380_select(struct Scsi_Host *instance, struct scsi_cmnd *cmd)
        spin_unlock_irq(instance->host_lock);
        err = NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, SR_REQ, HZ);
        spin_lock_irq(instance->host_lock);
-       
        if (err < 0) {
-               printk(KERN_ERR "scsi%d: timeout at NCR5380.c:%d\n", instance->host_no, __LINE__);
+               shost_printk(KERN_ERR, instance, "select: REQ timeout\n");
+               NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
                NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
                return -1;
        }

diff --git a/drivers/scsi/atari_NCR5380.c b/drivers/scsi/atari_NCR5380.c
index a3c0968c8eef7ed407a10e64e0e151c7fb562b9e..a92e4a531d34afa34261259fe6cc030e3a16840b 100644 (file)
--- a/drivers/scsi/atari_NCR5380.c
+++ b/drivers/scsi/atari_NCR5380.c
@@ -1412,6 +1412,7 @@ static int NCR5380_select(struct Scsi_Host *instance, struct scsi_cmnd *cmd)
        int len;
        int err;
        unsigned long flags;
+       unsigned long timeout;
 
        NCR5380_dprint(NDEBUG_ARBITRATION, instance);
        dprintk(NDEBUG_ARBITRATION, "scsi%d: starting arbitration, id = %d\n", HOSTNO,
@@ -1436,42 +1437,28 @@ static int NCR5380_select(struct Scsi_Host *instance, struct scsi_cmnd *cmd)
        NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
        NCR5380_write(MODE_REG, MR_ARBITRATE);
 
-       local_irq_restore(flags);
-
-       /* Wait for arbitration logic to complete */
-#if defined(NCR_TIMEOUT)
-       {
-               unsigned long timeout = jiffies + 2*NCR_TIMEOUT;
+       /* The chip now waits for BUS FREE phase. Then after the 800 ns
+        * Bus Free Delay, arbitration will begin.
+        */
 
-               while (!(NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_PROGRESS) &&
-                      time_before(jiffies, timeout) && !hostdata->connected)
-                       ;
-               if (time_after_eq(jiffies, timeout)) {
-                       printk("scsi : arbitration timeout at %d\n", __LINE__);
+       local_irq_restore(flags);
+       timeout = jiffies + HZ;
+       while (1) {
+               if (time_is_before_jiffies(timeout)) {
                        NCR5380_write(MODE_REG, MR_BASE);
-                       NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
+                       shost_printk(KERN_ERR, instance,
+                                    "select: arbitration timeout\n");
                        return -1;
                }
+               if (!(NCR5380_read(MODE_REG) & MR_ARBITRATE)) {
+                       /* Reselection interrupt */
+                       return -1;
+               }
+               if (NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_PROGRESS)
+                       break;
        }
-#else /* NCR_TIMEOUT */
-       while (!(NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_PROGRESS) &&
-              !hostdata->connected)
-               ;
-#endif
-
-       dprintk(NDEBUG_ARBITRATION, "scsi%d: arbitration complete\n", HOSTNO);
-
-       if (hostdata->connected) {
-               NCR5380_write(MODE_REG, MR_BASE);
-               return -1;
-       }
-       /*
-        * The arbitration delay is 2.2us, but this is a minimum and there is
-        * no maximum so we can safely sleep for ceil(2.2) usecs to accommodate
-        * the integral nature of udelay().
-        *
-        */
 
+       /* The SCSI-2 arbitration delay is 2.4 us */
        udelay(3);
 
        /* Check for lost arbitration */
@@ -1634,8 +1621,14 @@ static int NCR5380_select(struct Scsi_Host *instance, struct scsi_cmnd *cmd)
         */
 
        /* Wait for start of REQ/ACK handshake */
-       while (!(NCR5380_read(STATUS_REG) & SR_REQ))
-               ;
+
+       err = NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, SR_REQ, HZ);
+       if (err < 0) {
+               shost_printk(KERN_ERR, instance, "select: REQ timeout\n");
+               NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
+               NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
+               return -1;
+       }
 
        dprintk(NDEBUG_SELECTION, "scsi%d: target %d selected, going into MESSAGE OUT phase.\n",
                   HOSTNO, cmd->device->id);