3 files changed, 37 insertions, 18 deletions

diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index 2c0d0ec8150b..3b1ea34e1f5a 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -1070,8 +1070,8 @@ EXPORT_SYMBOL_GPL(scsi_get_vpd_page);
  * @opcode:     opcode for command to look up
  *
  * Uses the REPORT SUPPORTED OPERATION CODES to look up the given
- * opcode. Returns 0 if RSOC fails or if the command opcode is
- * unsupported. Returns 1 if the device claims to support the command.
+ * opcode. Returns -EINVAL if RSOC fails, 0 if the command opcode is
+ * unsupported and 1 if the device claims to support the command.
  */
 int scsi_report_opcode(struct scsi_device *sdev, unsigned char *buffer,
                        unsigned int len, unsigned char opcode)
@@ -1081,7 +1081,7 @@ int scsi_report_opcode(struct scsi_device *sdev, unsigned char *buffer,
         int result;
 
         if (sdev->no_report_opcodes || sdev->scsi_level < SCSI_SPC_3)
-                return 0;
+                return -EINVAL;
 
         memset(cmd, 0, 16);
         cmd[0] = MAINTENANCE_IN;
@@ -1097,7 +1097,7 @@ int scsi_report_opcode(struct scsi_device *sdev, unsigned char *buffer,
         if (result && scsi_sense_valid(&sshdr) &&
             sshdr.sense_key == ILLEGAL_REQUEST &&
             (sshdr.asc == 0x20 || sshdr.asc == 0x24) && sshdr.ascq == 0x00)
-                return 0;
+                return -EINVAL;
 
         if ((buffer[1] & 3) == 3) /* Command supported */
                 return 1;
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 91e8a953d1de..34da1a1acb09 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -442,8 +442,10 @@ sd_store_write_same_blocks(struct device *dev, struct device_attribute *attr,
 
         if (max == 0)
                 sdp->no_write_same = 1;
-        else if (max <= SD_MAX_WS16_BLOCKS)
+        else if (max <= SD_MAX_WS16_BLOCKS) {
+                sdp->no_write_same = 0;
                 sdkp->max_ws_blocks = max;
+        }
 
         sd_config_write_same(sdkp);
 
@@ -750,7 +752,6 @@ static void sd_config_write_same(struct scsi_disk *sdkp)
 {
         struct request_queue *q = sdkp->disk->queue;
         unsigned int logical_block_size = sdkp->device->sector_size;
-        unsigned int blocks = 0;
 
         if (sdkp->device->no_write_same) {
                 sdkp->max_ws_blocks = 0;
@@ -762,18 +763,20 @@ static void sd_config_write_same(struct scsi_disk *sdkp)
          * blocks per I/O unless the device explicitly advertises a
          * bigger limit.
          */
-        if (sdkp->max_ws_blocks == 0)
-                sdkp->max_ws_blocks = SD_MAX_WS10_BLOCKS;
-
-        if (sdkp->ws16 || sdkp->max_ws_blocks > SD_MAX_WS10_BLOCKS)
-                blocks = min_not_zero(sdkp->max_ws_blocks,
-                                      (u32)SD_MAX_WS16_BLOCKS);
-        else
-                blocks = min_not_zero(sdkp->max_ws_blocks,
-                                      (u32)SD_MAX_WS10_BLOCKS);
+        if (sdkp->max_ws_blocks > SD_MAX_WS10_BLOCKS)
+                sdkp->max_ws_blocks = min_not_zero(sdkp->max_ws_blocks,
+                                                   (u32)SD_MAX_WS16_BLOCKS);
+        else if (sdkp->ws16 || sdkp->ws10 || sdkp->device->no_report_opcodes)
+                sdkp->max_ws_blocks = min_not_zero(sdkp->max_ws_blocks,
+                                                   (u32)SD_MAX_WS10_BLOCKS);
+        else {
+                sdkp->device->no_write_same = 1;
+                sdkp->max_ws_blocks = 0;
+        }
 
 out:
-        blk_queue_max_write_same_sectors(q, blocks * (logical_block_size >> 9));
+        blk_queue_max_write_same_sectors(q, sdkp->max_ws_blocks *
+                                         (logical_block_size >> 9));
 }
 
 /**
@@ -2645,9 +2648,24 @@ static void sd_read_block_provisioning(struct scsi_disk *sdkp)
 
 static void sd_read_write_same(struct scsi_disk *sdkp, unsigned char *buffer)
 {
-        if (scsi_report_opcode(sdkp->device, buffer, SD_BUF_SIZE,
-                               WRITE_SAME_16))
+        struct scsi_device *sdev = sdkp->device;
+
+        if (scsi_report_opcode(sdev, buffer, SD_BUF_SIZE, INQUIRY) < 0) {
+                sdev->no_report_opcodes = 1;
+
+                /* Disable WRITE SAME if REPORT SUPPORTED OPERATION
+                 * CODES is unsupported and the device has an ATA
+                 * Information VPD page (SAT).
+                 */
+                if (!scsi_get_vpd_page(sdev, 0x89, buffer, SD_BUF_SIZE))
+                        sdev->no_write_same = 1;
+        }
+
+        if (scsi_report_opcode(sdev, buffer, SD_BUF_SIZE, WRITE_SAME_16) == 1)
                 sdkp->ws16 = 1;
+
+        if (scsi_report_opcode(sdev, buffer, SD_BUF_SIZE, WRITE_SAME) == 1)
+                sdkp->ws10 = 1;
 }
 
 static int sd_try_extended_inquiry(struct scsi_device *sdp)
diff --git a/drivers/scsi/sd.h b/drivers/scsi/sd.h
index 2386aeb41fe8..7a049de22051 100644
--- a/drivers/scsi/sd.h
+++ b/drivers/scsi/sd.h
@@ -84,6 +84,7 @@ struct scsi_disk {
         unsigned        lbpws : 1;
         unsigned        lbpws10 : 1;
         unsigned        lbpvpd : 1;
+        unsigned        ws10 : 1;
         unsigned        ws16 : 1;
 };
 #define to_scsi_disk(obj) container_of(obj,struct scsi_disk,dev)