Host sends MODE_SENSE_10 with caching mode page, to check if the device
supports the cache feature.
Some LLD standards requires DBD field to be set to 1.
Change-Id: I0c8752c1888654942d6d7e6e0f6dc197033ac326
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index aab4ed8..6d8194f 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -2629,6 +2629,7 @@ static int sd_try_rc16_first(struct scsi_device *sdp)
{
int len = 0, res;
struct scsi_device *sdp = sdkp->device;
+ struct Scsi_Host *host = sdp->host;
int dbd;
int modepage;
@@ -2660,7 +2661,10 @@ static int sd_try_rc16_first(struct scsi_device *sdp)
dbd = 8;
} else {
modepage = 8;
- dbd = 0;
+ if (host->set_dbd_for_caching)
+ dbd = 8;
+ else
+ dbd = 0;
}
/* cautiously ask */
diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index 2c3f0c5..3900987 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -650,6 +650,12 @@ struct Scsi_Host {
unsigned no_scsi2_lun_in_cdb:1;
/*
+ * Set "DBD" field in mode_sense caching mode page in case it is
+ * mandatory by LLD standard.
+ */
+ unsigned set_dbd_for_caching:1;
+
+ /*
* Optional work queue to be utilized by the transport
*/
char work_q_name[20];