[SCSI] qla4xxx: Add support for ql4xmaxqdepth command line parameter
This provides the flexibility to modify the qdepth based on different
target devices to make the best use of system resources.
Signed-off-by: Vikas Chaudhary <vikas.chaudhary@qlogic.com>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
diff --git a/drivers/scsi/qla4xxx/ql4_os.c b/drivers/scsi/qla4xxx/ql4_os.c
index f80b702..df46e5d 100644
--- a/drivers/scsi/qla4xxx/ql4_os.c
+++ b/drivers/scsi/qla4xxx/ql4_os.c
@@ -51,6 +51,11 @@
" 2 = enable MSI interrupt mechanism.");
#define QL4_DEF_QDEPTH 32
+static int ql4xmaxqdepth = QL4_DEF_QDEPTH;
+module_param(ql4xmaxqdepth, int, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(ql4xmaxqdepth,
+ "Maximum queue depth to report for target devices.\n"
+ " Default: 32.");
/*
* SCSI host template entry points
@@ -1904,10 +1909,15 @@
{
struct iscsi_cls_session *sess = starget_to_session(sdev->sdev_target);
struct ddb_entry *ddb = sess->dd_data;
+ int queue_depth = QL4_DEF_QDEPTH;
sdev->hostdata = ddb;
sdev->tagged_supported = 1;
- scsi_activate_tcq(sdev, QL4_DEF_QDEPTH);
+
+ if (ql4xmaxqdepth != 0 && ql4xmaxqdepth <= 0xffffU)
+ queue_depth = ql4xmaxqdepth;
+
+ scsi_activate_tcq(sdev, queue_depth);
return 0;
}