[SCSI] ibmvscsi: Make max_requests module parameter more accurate
In a previous patch to fix an issue with error recovery,
the behavior of the max_requests module paramater was also
changed. If, for some reason, max_requests is set to one by
the user, we will end up with a negative number for can_queue.
Fix this by making max_requests not include the two event structs
needed to do error recovery.
Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
diff --git a/drivers/scsi/ibmvscsi/ibmvscsi.c b/drivers/scsi/ibmvscsi/ibmvscsi.c
index 868d35e..5c541f7 100644
--- a/drivers/scsi/ibmvscsi/ibmvscsi.c
+++ b/drivers/scsi/ibmvscsi/ibmvscsi.c
@@ -89,6 +89,7 @@
static int max_channel = 3;
static int init_timeout = 5;
static int max_requests = IBMVSCSI_MAX_REQUESTS_DEFAULT;
+static int max_events = IBMVSCSI_MAX_REQUESTS_DEFAULT + 2;
static struct scsi_transport_template *ibmvscsi_transport_template;
@@ -1633,7 +1634,7 @@
static unsigned long ibmvscsi_get_desired_dma(struct vio_dev *vdev)
{
/* iu_storage data allocated in initialize_event_pool */
- unsigned long desired_io = max_requests * sizeof(union viosrp_iu);
+ unsigned long desired_io = max_events * sizeof(union viosrp_iu);
/* add io space for sg data */
desired_io += (IBMVSCSI_MAX_SECTORS_DEFAULT * 512 *
@@ -1657,7 +1658,6 @@
vdev->dev.driver_data = NULL;
- driver_template.can_queue = max_requests - 2;
host = scsi_host_alloc(&driver_template, sizeof(*hostdata));
if (!host) {
dev_err(&vdev->dev, "couldn't allocate host data\n");
@@ -1673,12 +1673,12 @@
atomic_set(&hostdata->request_limit, -1);
hostdata->host->max_sectors = IBMVSCSI_MAX_SECTORS_DEFAULT;
- rc = ibmvscsi_ops->init_crq_queue(&hostdata->queue, hostdata, max_requests);
+ rc = ibmvscsi_ops->init_crq_queue(&hostdata->queue, hostdata, max_events);
if (rc != 0 && rc != H_RESOURCE) {
dev_err(&vdev->dev, "couldn't initialize crq. rc=%d\n", rc);
goto init_crq_failed;
}
- if (initialize_event_pool(&hostdata->pool, max_requests, hostdata) != 0) {
+ if (initialize_event_pool(&hostdata->pool, max_events, hostdata) != 0) {
dev_err(&vdev->dev, "couldn't initialize event pool\n");
goto init_pool_failed;
}
@@ -1730,7 +1730,7 @@
add_host_failed:
release_event_pool(&hostdata->pool, hostdata);
init_pool_failed:
- ibmvscsi_ops->release_crq_queue(&hostdata->queue, hostdata, max_requests);
+ ibmvscsi_ops->release_crq_queue(&hostdata->queue, hostdata, max_events);
init_crq_failed:
scsi_host_put(host);
scsi_host_alloc_failed:
@@ -1742,7 +1742,7 @@
struct ibmvscsi_host_data *hostdata = vdev->dev.driver_data;
release_event_pool(&hostdata->pool, hostdata);
ibmvscsi_ops->release_crq_queue(&hostdata->queue, hostdata,
- max_requests);
+ max_events);
srp_remove_host(hostdata->host);
scsi_remove_host(hostdata->host);
@@ -1779,6 +1779,10 @@
{
int ret;
+ /* Ensure we have two requests to do error recovery */
+ driver_template.can_queue = max_requests;
+ max_events = max_requests + 2;
+
if (firmware_has_feature(FW_FEATURE_ISERIES))
ibmvscsi_ops = &iseriesvscsi_ops;
else if (firmware_has_feature(FW_FEATURE_VIO))