2 files changed, 59 insertions, 14 deletions

diff --git a/drivers/scsi/scsi_pm.c b/drivers/scsi/scsi_pm.c
index 4c5aabe21755..af4c050ce6e4 100644
--- a/drivers/scsi/scsi_pm.c
+++ b/drivers/scsi/scsi_pm.c
@@ -54,7 +54,8 @@ scsi_bus_suspend_common(struct device *dev, int (*cb)(struct device *))
 		/*
 		 * All the high-level SCSI drivers that implement runtime
 		 * PM treat runtime suspend, system suspend, and system
-		 * hibernate identically.
+		 * hibernate nearly identically. In all cases the requirements
+		 * for runtime suspension are stricter.
 		 */
 		if (pm_runtime_suspended(dev))
 			return 0;
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index ab96b793f904..3824e754ca1d 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -105,7 +105,8 @@ static void sd_unlock_native_capacity(struct gendisk *disk);
 static int  sd_probe(struct device *);
 static int  sd_remove(struct device *);
 static void sd_shutdown(struct device *);
-static int sd_suspend(struct device *);
+static int sd_suspend_system(struct device *);
+static int sd_suspend_runtime(struct device *);
 static int sd_resume(struct device *);
 static void sd_rescan(struct device *);
 static int sd_done(struct scsi_cmnd *);
@@ -484,11 +485,11 @@ static struct class sd_disk_class = {
 };
 
 static const struct dev_pm_ops sd_pm_ops = {
-	.suspend		= sd_suspend,
+	.suspend		= sd_suspend_system,
 	.resume			= sd_resume,
-	.poweroff		= sd_suspend,
+	.poweroff		= sd_suspend_system,
 	.restore		= sd_resume,
-	.runtime_suspend	= sd_suspend,
+	.runtime_suspend	= sd_suspend_runtime,
 	.runtime_resume		= sd_resume,
 };
 
@@ -1438,7 +1439,6 @@ static int sd_sync_cache(struct scsi_disk *sdkp)
 	if (!scsi_device_online(sdp))
 		return -ENODEV;
 
-
 	for (retries = 3; retries > 0; --retries) {
 		unsigned char cmd[10] = { 0 };
 
@@ -1456,12 +1456,31 @@ static int sd_sync_cache(struct scsi_disk *sdkp)
 
 	if (res) {
 		sd_print_result(sdkp, res);
+
 		if (driver_byte(res) & DRIVER_SENSE)
 			sd_print_sense_hdr(sdkp, &sshdr);
+		/* we need to evaluate the error return  */
+		if (scsi_sense_valid(&sshdr) &&
+			/* 0x3a is medium not present */
+			sshdr.asc == 0x3a)
+				/* this is no error here */
+				return 0;
+
+		switch (host_byte(res)) {
+		/* ignore errors due to racing a disconnection */
+		case DID_BAD_TARGET:
+		case DID_NO_CONNECT:
+			return 0;
+		/* signal the upper layer it might try again */
+		case DID_BUS_BUSY:
+		case DID_IMM_RETRY:
+		case DID_REQUEUE:
+		case DID_SOFT_ERROR:
+			return -EBUSY;
+		default:
+			return -EIO;
+		}
 	}
-
-	if (res)
-		return -EIO;
 	return 0;
 }
 
@@ -3061,9 +3080,17 @@ static int sd_start_stop_device(struct scsi_disk *sdkp, int start)
 		sd_print_result(sdkp, res);
 		if (driver_byte(res) & DRIVER_SENSE)
 			sd_print_sense_hdr(sdkp, &sshdr);
+		if (scsi_sense_valid(&sshdr) &&
+			/* 0x3a is medium not present */
+			sshdr.asc == 0x3a)
+			res = 0;
 	}
 
-	return res;
+	/* SCSI error codes must not go to the generic layer */
+	if (res)
+		return -EIO;
+
+	return 0;
 }
 
 /*
@@ -3081,7 +3108,7 @@ static void sd_shutdown(struct device *dev)
 	if (pm_runtime_suspended(dev))
 		goto exit;
 
-	if (sdkp->WCE) {
+	if (sdkp->WCE && sdkp->media_present) {
 		sd_printk(KERN_NOTICE, sdkp, "Synchronizing SCSI cache\n");
 		sd_sync_cache(sdkp);
 	}
@@ -3095,7 +3122,7 @@ exit:
 	scsi_disk_put(sdkp);
 }
 
-static int sd_suspend(struct device *dev)
+static int sd_suspend_common(struct device *dev, bool ignore_stop_errors)
 {
 	struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
 	int ret = 0;
@@ -3103,16 +3130,23 @@ static int sd_suspend(struct device *dev)
 	if (!sdkp)
 		return 0;	/* this can happen */
 
-	if (sdkp->WCE) {
+	if (sdkp->WCE && sdkp->media_present) {
 		sd_printk(KERN_NOTICE, sdkp, "Synchronizing SCSI cache\n");
 		ret = sd_sync_cache(sdkp);
-		if (ret)
+		if (ret) {
+			/* ignore OFFLINE device */
+			if (ret == -ENODEV)
+				ret = 0;
 			goto done;
+		}
 	}
 
 	if (sdkp->device->manage_start_stop) {
 		sd_printk(KERN_NOTICE, sdkp, "Stopping disk\n");
+		/* an error is not worth aborting a system sleep */
 		ret = sd_start_stop_device(sdkp, 0);
+		if (ignore_stop_errors)
+			ret = 0;
 	}
 
 done:
@@ -3120,6 +3154,16 @@ done:
 	return ret;
 }
 
+static int sd_suspend_system(struct device *dev)
+{
+	return sd_suspend_common(dev, true);
+}
+
+static int sd_suspend_runtime(struct device *dev)
+{
+	return sd_suspend_common(dev, false);
+}
+
 static int sd_resume(struct device *dev)
 {
 	struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);