[SCSI] aacraid: Changeable queue depth
Inspired by Brian King's patch to the ibmvscsi driver. Adds support for
a changeable queue depth to the aacraid driver.
Signed-off-by: Mark Salyzyn <aacraid@adaptec.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
diff --git a/drivers/scsi/aacraid/linit.c b/drivers/scsi/aacraid/linit.c
index a270a3f..6f92d07 100644
--- a/drivers/scsi/aacraid/linit.c
+++ b/drivers/scsi/aacraid/linit.c
@@ -446,6 +446,43 @@
return 0;
}
+/**
+ * aac_change_queue_depth - alter queue depths
+ * @sdev: SCSI device we are considering
+ * @depth: desired queue depth
+ *
+ * Alters queue depths for target device based on the host adapter's
+ * total capacity and the queue depth supported by the target device.
+ */
+
+static int aac_change_queue_depth(struct scsi_device *sdev, int depth)
+{
+ if (sdev->tagged_supported && (sdev->type == TYPE_DISK) &&
+ (sdev_channel(sdev) == CONTAINER_CHANNEL)) {
+ struct scsi_device * dev;
+ struct Scsi_Host *host = sdev->host;
+ unsigned num = 0;
+
+ __shost_for_each_device(dev, host) {
+ if (dev->tagged_supported && (dev->type == TYPE_DISK) &&
+ (sdev_channel(dev) == CONTAINER_CHANNEL))
+ ++num;
+ ++num;
+ }
+ if (num >= host->can_queue)
+ num = host->can_queue - 1;
+ if (depth > (host->can_queue - num))
+ depth = host->can_queue - num;
+ if (depth > 256)
+ depth = 256;
+ else if (depth < 2)
+ depth = 2;
+ scsi_adjust_queue_depth(sdev, MSG_ORDERED_TAG, depth);
+ } else
+ scsi_adjust_queue_depth(sdev, 0, 1);
+ return sdev->queue_depth;
+}
+
static int aac_ioctl(struct scsi_device *sdev, int cmd, void __user * arg)
{
struct aac_dev *dev = (struct aac_dev *)sdev->host->hostdata;
@@ -844,6 +881,7 @@
.bios_param = aac_biosparm,
.shost_attrs = aac_attrs,
.slave_configure = aac_slave_configure,
+ .change_queue_depth = aac_change_queue_depth,
.eh_abort_handler = aac_eh_abort,
.eh_host_reset_handler = aac_eh_reset,
.can_queue = AAC_NUM_IO_FIB,