diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index a5986dae9020..828b27188f28 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -6,7 +6,7 @@
  *  anything out of the ordinary is seen.
  * ^^^^^^^^^^^^^^^^^^^^^^^ Original ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  *
- * Copyright (C) 2001 - 2017 Douglas Gilbert
+ * Copyright (C) 2001 - 2018 Douglas Gilbert
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -61,8 +61,8 @@
 #include "scsi_logging.h"
 
 /* make sure inq_product_rev string corresponds to this version */
-#define SDEBUG_VERSION "0187"	/* format to fit INQUIRY revision field */
-static const char *sdebug_version_date = "20171202";
+#define SDEBUG_VERSION "0188"	/* format to fit INQUIRY revision field */
+static const char *sdebug_version_date = "20180128";
 
 #define MY_NAME "scsi_debug"
 
@@ -234,6 +234,7 @@ static const char *sdebug_version_date = "20171202";
 #define F_INV_OP		0x200
 #define F_FAKE_RW		0x400
 #define F_M_ACCESS		0x800	/* media access */
+#define F_LONG_DELAY		0x1000
 
 #define FF_RESPOND (F_RL_WLUN_OK | F_SKIP_UA | F_DELAY_OVERR)
 #define FF_MEDIA_IO (F_M_ACCESS | F_FAKE_RW)
@@ -349,7 +350,7 @@ enum sdeb_opcode_index {
 	SDEB_I_XDWRITEREAD = 25,	/* 10 only */
 	SDEB_I_WRITE_BUFFER = 26,
 	SDEB_I_WRITE_SAME = 27,		/* 10, 16 */
-	SDEB_I_SYNC_CACHE = 28,		/* 10 only */
+	SDEB_I_SYNC_CACHE = 28,		/* 10, 16 */
 	SDEB_I_COMP_WRITE = 29,
 	SDEB_I_LAST_ELEMENT = 30,	/* keep this last (previous + 1) */
 };
@@ -382,7 +383,7 @@ static const unsigned char opcode_ind_arr[256] = {
 /* 0x80; 0x80->0x9f: 16 byte cdbs */
 	0, 0, 0, 0, 0, SDEB_I_ATA_PT, 0, 0,
 	SDEB_I_READ, SDEB_I_COMP_WRITE, SDEB_I_WRITE, 0, 0, 0, 0, 0,
-	0, 0, 0, SDEB_I_WRITE_SAME, 0, 0, 0, 0,
+	0, SDEB_I_SYNC_CACHE, 0, SDEB_I_WRITE_SAME, 0, 0, 0, 0,
 	0, 0, 0, 0, 0, 0, SDEB_I_SERV_ACT_IN_16, SDEB_I_SERV_ACT_OUT_16,
 /* 0xa0; 0xa0->0xbf: 12 byte cdbs */
 	SDEB_I_REPORT_LUNS, SDEB_I_ATA_PT, 0, SDEB_I_MAINT_IN,
@@ -398,6 +399,14 @@ static const unsigned char opcode_ind_arr[256] = {
 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 };
 
+/*
+ * The following "response" functions return the SCSI mid-level's 4 byte
+ * tuple-in-an-int. To handle commands with an IMMED bit, for a faster
+ * command completion, they can mask their return value with
+ * SDEG_RES_IMMED_MASK .
+ */
+#define SDEG_RES_IMMED_MASK 0x40000000
+
 static int resp_inquiry(struct scsi_cmnd *, struct sdebug_dev_info *);
 static int resp_report_luns(struct scsi_cmnd *, struct sdebug_dev_info *);
 static int resp_requests(struct scsi_cmnd *, struct sdebug_dev_info *);
@@ -420,6 +429,7 @@ static int resp_write_same_16(struct scsi_cmnd *, struct sdebug_dev_info *);
 static int resp_xdwriteread_10(struct scsi_cmnd *, struct sdebug_dev_info *);
 static int resp_comp_write(struct scsi_cmnd *, struct sdebug_dev_info *);
 static int resp_write_buffer(struct scsi_cmnd *, struct sdebug_dev_info *);
+static int resp_sync_cache(struct scsi_cmnd *, struct sdebug_dev_info *);
 
 /*
  * The following are overflow arrays for cdbs that "hit" the same index in
@@ -499,6 +509,12 @@ static const struct opcode_info_t release_iarr[] = {
 	    {6,  0x1f, 0xff, 0, 0, 0xc7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
 };
 
+static const struct opcode_info_t sync_cache_iarr[] = {
+	{0, 0x91, 0, F_LONG_DELAY | F_M_ACCESS, resp_sync_cache, NULL,
+	    {16,  0x6, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+	     0xff, 0xff, 0xff, 0xff, 0x3f, 0xc7} },	/* SYNC_CACHE (16) */
+};
+
 
 /* This array is accessed via SDEB_I_* values. Make sure all are mapped,
  * plus the terminating elements for logic that scans this table such as
@@ -536,8 +552,8 @@ static const struct opcode_info_t opcode_info_arr[SDEB_I_LAST_ELEMENT + 1] = {
 	{ARRAY_SIZE(write_iarr), 0x8a, 0, F_D_OUT | FF_MEDIA_IO,
 	    resp_write_dt0, write_iarr,			/* WRITE(16) */
 		{16,  0xfa, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
-		 0xff, 0xff, 0xff, 0xff, 0xff, 0xc7} },		/* WRITE(16) */
-	{0, 0x1b, 0, 0, resp_start_stop, NULL,		/* START STOP UNIT */
+		 0xff, 0xff, 0xff, 0xff, 0xff, 0xc7} },
+	{0, 0x1b, 0, F_LONG_DELAY, resp_start_stop, NULL,/* START STOP UNIT */
 	    {6,  0x1, 0, 0xf, 0xf7, 0xc7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
 	{ARRAY_SIZE(sa_in_16_iarr), 0x9e, 0x10, F_SA_LOW | F_D_IN,
 	    resp_readcap16, sa_in_16_iarr, /* SA_IN(16), READ CAPACITY(16) */
@@ -590,9 +606,10 @@ static const struct opcode_info_t opcode_info_arr[SDEB_I_LAST_ELEMENT + 1] = {
 	    resp_write_same_10, write_same_iarr,	/* WRITE SAME(10) */
 		{10,  0xff, 0xff, 0xff, 0xff, 0xff, 0x3f, 0xff, 0xff, 0xc7, 0,
 		 0, 0, 0, 0, 0} },
-	{0, 0x35, 0, F_DELAY_OVERR | FF_MEDIA_IO, NULL, NULL, /* SYNC_CACHE */
+	{ARRAY_SIZE(sync_cache_iarr), 0x35, 0, F_LONG_DELAY | F_M_ACCESS,
+	    resp_sync_cache, sync_cache_iarr,
 	    {10,  0x7, 0xff, 0xff, 0xff, 0xff, 0x3f, 0xff, 0xff, 0xc7, 0, 0,
-	     0, 0, 0, 0} },
+	     0, 0, 0, 0} },			/* SYNC_CACHE (10) */
 	{0, 0x89, 0, F_D_OUT | FF_MEDIA_IO, resp_comp_write, NULL,
 	    {16,  0xf8, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0, 0,
 	     0, 0xff, 0x3f, 0xc7} },		/* COMPARE AND WRITE */
@@ -1597,7 +1614,7 @@ static int resp_start_stop(struct scsi_cmnd * scp,
 	}
 	stop = !(cmd[4] & 1);
 	atomic_xchg(&devip->stopped, stop);
-	return 0;
+	return (cmd[1] & 0x1) ? SDEG_RES_IMMED_MASK : 0; /* check IMMED bit */
 }
 
 static sector_t get_sdebug_capacity(void)
@@ -3562,6 +3579,27 @@ static int resp_get_lba_status(struct scsi_cmnd *scp,
 	return fill_from_dev_buffer(scp, arr, SDEBUG_GET_LBA_STATUS_LEN);
 }
 
+static int resp_sync_cache(struct scsi_cmnd *scp,
+			   struct sdebug_dev_info *devip)
+{
+	u64 lba;
+	u32 num_blocks;
+	u8 *cmd = scp->cmnd;
+
+	if (cmd[0] == SYNCHRONIZE_CACHE) {	/* 10 byte cdb */
+		lba = get_unaligned_be32(cmd + 2);
+		num_blocks = get_unaligned_be16(cmd + 7);
+	} else {				/* SYNCHRONIZE_CACHE(16) */
+		lba = get_unaligned_be64(cmd + 2);
+		num_blocks = get_unaligned_be32(cmd + 10);
+	}
+	if (lba + num_blocks > sdebug_capacity) {
+		mk_sense_buffer(scp, ILLEGAL_REQUEST, LBA_OUT_OF_RANGE, 0);
+		return check_condition_result;
+	}
+	return (cmd[1] & 0x2) ? SDEG_RES_IMMED_MASK : 0; /* check IMMED bit */
+}
+
 #define RL_BUCKET_ELEMS 8
 
 /* Even though each pseudo target has a REPORT LUNS "well known logical unit"
@@ -5717,11 +5755,27 @@ static int scsi_debug_queuecommand(struct Scsi_Host *shost,
 		errsts = oip->pfp(scp, devip);	/* calls a resp_* function */
 	else if (r_pfp)	/* if leaf function ptr NULL, try the root's */
 		errsts = r_pfp(scp, devip);
+	if (errsts & SDEG_RES_IMMED_MASK) {
+		errsts &= ~SDEG_RES_IMMED_MASK;
+		flags |= F_DELAY_OVERR;
+		flags &= ~F_LONG_DELAY;
+	}
+
 
 fini:
 	if (F_DELAY_OVERR & flags)
 		return schedule_resp(scp, devip, errsts, 0, 0);
-	else
+	else if ((sdebug_jdelay || sdebug_ndelay) && (flags & F_LONG_DELAY)) {
+		/*
+		 * If any delay is active, want F_LONG_DELAY to be at least 1
+		 * second and if sdebug_jdelay>0 want a long delay of that
+		 * many seconds.
+		 */
+		int jdelay = (sdebug_jdelay < 2) ? 1 : sdebug_jdelay;
+
+		jdelay = mult_frac(USER_HZ * jdelay, HZ, USER_HZ);
+		return schedule_resp(scp, devip, errsts, jdelay, 0);
+	} else
 		return schedule_resp(scp, devip, errsts, sdebug_jdelay,
 				     sdebug_ndelay);
 check_cond:
