1 files changed, 32 insertions, 14 deletions

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 91e8a95..34da1a1 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)