Commit 5c9cfedd authored by Salyzyn, Mark's avatar Salyzyn, Mark Committed by James Bottomley

[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: default avatarMark Salyzyn <aacraid@adaptec.com>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@SteelEye.com>
parent 32fbac22
......@@ -446,6 +446,43 @@ static int aac_slave_configure(struct scsi_device *sdev)
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 @@ static struct scsi_host_template aac_driver_template = {
.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,
......
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