[PATCH] Remove sync waiting code from libata

[Matthew Wilcox <matthew@wil.cx>]

By using the scsi async probing code, we can remove the 'sync' argument
from ata_scsi_scan_host():

diff -u b/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
--- b/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -6362,10 +6362,15 @@
 	}
 }
 
+/*
+ * Give ourselves ten seconds to find everything.
+ * This should be more than enough time
+ */
 int ata_scsi_scan_finished(struct Scsi_Host *shost, unsigned long time)
 {
-	ata_scsi_scan_host(ata_shost_to_port(shost), 1);
-	return 1;
+	if (ata_scsi_scan_host(ata_shost_to_port(shost)))
+		return 1;
+	return time > (10 * HZ);
 }
 
 /**
diff -u b/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
--- b/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -2954,17 +2954,15 @@
 	return rc;
 }
 
-void ata_scsi_scan_host(struct ata_port *ap, int sync)
+/* Returns 1 if we are done scanning, 0 if we've scheduled async scanning */
+int ata_scsi_scan_host(struct ata_port *ap)
 {
-	int tries = 5;
-	struct ata_device *last_failed_dev = NULL;
 	struct ata_device *dev;
 	unsigned int i;
 
 	if (ap->flags & ATA_FLAG_DISABLED)
-		return;
+		return 1;
 
- repeat:
 	for (i = 0; i < ATA_MAX_DEVICES; i++) {
 		struct scsi_device *sdev;
 
@@ -2990,34 +2988,11 @@
 			break;
 	}
 	if (i == ATA_MAX_DEVICES)
-		return;
-
-	/* we're missing some SCSI devices */
-	if (sync) {
-		/* If caller requested synchrnous scan && we've made
-		 * any progress, sleep briefly and repeat.
-		 */
-		if (dev != last_failed_dev) {
-			msleep(100);
-			last_failed_dev = dev;
-			goto repeat;
-		}
-
-		/* We might be failing to detect boot device, give it
-		 * a few more chances.
-		 */
-		if (--tries) {
-			msleep(100);
-			goto repeat;
-		}
-
-		ata_port_printk(ap, KERN_ERR, "WARNING: synchronous SCSI scan "
-				"failed without making any progress,\n"
-				"                  switching to async\n");
-	}
+		return 1;
 
 	queue_delayed_work(ata_aux_wq, &ap->hotplug_task,
 			   round_jiffies_relative(HZ));
+	return 0;
 }
 
 /**
@@ -3144,7 +3119,7 @@
 	}
 
 	/* scan for new ones */
-	ata_scsi_scan_host(ap, 0);
+	ata_scsi_scan_host(ap);
 
 	DPRINTK("EXIT\n");
 }
only in patch2:
unchanged:
--- a/drivers/ata/libata.h
+++ b/drivers/ata/libata.h
@@ -112,7 +112,7 @@ static inline int ata_acpi_on_devcfg(struct ata_device *adev) { return 0; }
 /* libata-scsi.c */
 extern int ata_scsi_add_hosts(struct ata_host *host,
 			      struct scsi_host_template *sht);
-extern void ata_scsi_scan_host(struct ata_port *ap, int sync);
+extern int ata_scsi_scan_host(struct ata_port *ap);
 extern int ata_scsi_offline_dev(struct ata_device *dev);
 extern void ata_scsi_hotplug(struct work_struct *work);
 extern unsigned int ata_scsiop_inq_std(struct ata_scsi_args *args, u8 *rbuf,

-- 
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"Bill, look, we understand that you're interested in selling us this
operating system, but compare it to ours.  We can't possibly take such
a retrograde step."