scsi: core: Adjust DBD setting in MODE SENSE for caching mode page per LLD

UFS JEDEC standards require DBD field to be set to 1 in mode sense
command.  This patch allows LLD to define the setting of DBD, if
required.

Link: https://lore.kernel.org/r/0101016ed3d643f9-ffd45d6c-c593-4a13-a18f-a32da3d3bb97-000000@us-west-2.amazonses.com
Reviewed-by: Avri Altman <avri.altman@wdc.com>
Signed-off-by: Can Guo <cang@codeaurora.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 3e7a45d..610ee41 100644 (file)
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -2108,6 +2108,8 @@ scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage,
 
        memset(data, 0, sizeof(*data));
        memset(&cmd[0], 0, 12);
+
+       dbd = sdev->set_dbd_for_ms ? 8 : dbd;
        cmd[1] = dbd & 0x18;    /* allows DBD and LLBA bits */
        cmd[2] = modepage;
 

diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index 3ed836d..f8312a3 100644 (file)
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -172,6 +172,7 @@ struct scsi_device {
                                     * because we did a bus reset. */
        unsigned use_10_for_rw:1; /* first try 10-byte read / write */
        unsigned use_10_for_ms:1; /* first try 10-byte mode sense/select */
+       unsigned set_dbd_for_ms:1; /* Set "DBD" field in mode sense */
        unsigned no_report_opcodes:1;   /* no REPORT SUPPORTED OPERATION CODES */
        unsigned no_write_same:1;       /* no WRITE SAME command */
        unsigned use_16_for_rw:1; /* Use read/write(16) over read/write(10) */