PATCH [2/8] scsi: megaraid_sas - add module param fast_load

bo yang
2007-09-28T20:04:47Z

Driver will skip physical devices scan for the first time if the fast_load is set. This is to reduce time for loading driver.

Signed-off-by: Bo Yang <bo.yang@lsi.com>

---
drivers/scsi/megaraid/megaraid_sas.c | 69 +++++++++++++++++++------
1 files changed, 55 insertions(+), 14 deletions(-)

diff -rupN linux-2.6.22_orig/drivers/scsi/megaraid/megaraid_sas.c linux-2.6.22_new/drivers/scsi/megaraid/megaraid_sas.c
--- linux-2.6.22_orig/drivers/scsi/megaraid/megaraid_sas.c 2007-09-26 16:19:18.321402040 -0400
+++ linux-2.6.22_new/drivers/scsi/megaraid/megaraid_sas.c 2007-09-26 16:20:52.915021624 -0400
@@ -46,6 +46,22 @@
#include <scsi/scsi_host.h>
#include "megaraid_sas.h"

+/*
+ * Module parameters
+ */
+
+/*
+ * Fast driver load option, skip scanning for physical devices during
+ * load. This would result in physical devices being skipped during
+ * driver load time. These can be later added though,
+ * using /proc/scsi/scsi
+ */
+static unsigned int fast_load;
+module_param_named(fast_load, fast_load, int, 0);
+MODULE_PARM_DESC(fast_load,
+ "megasas: Faster loading of the driver, skips physical devices! \
+ (default = 0)");
+
MODULE_LICENSE("GPL");
MODULE_VERSION(MEGASAS_VERSION);
MODULE_AUTHOR("megaraidlinux@lsi.com");
@@ -1094,6 +1110,44 @@ megasas_service_aen(struct megasas_insta
megasas_return_cmd(instance, cmd);
}

+static struct megasas_instance *megasas_lookup_instance(u16 host_no)
+{
+ int i;
+
+ for (i = 0; i < megasas_mgmt_info.max_index; i++) {
+ if ((megasas_mgmt_info.instance[i]) &&
+ (megasas_mgmt_info.instance[i]->host->host_no
+ == host_no))
+ return megasas_mgmt_info.instance[i];
+ }
+
+ return NULL;
+}
+
+static int megasas_slave_alloc(struct scsi_device *sdev)
+{
+ struct megasas_instance *instance;
+ int tmp_fastload = fast_load;
+
+ instance = megasas_lookup_instance(sdev->host->host_no);
+
+ if (tmp_fastload && sdev->channel < MEGASAS_MAX_PD_CHANNELS) {
+ if ((sdev->id == MEGASAS_MAX_DEV_PER_CHANNEL -1) &&
+ (sdev->channel == MEGASAS_MAX_PD_CHANNELS - 1)) {
+
+ /*
+ * If fast load option was set and scan for last device is
+ * over, reset the fast_load flag so that during a possible
+ * next scan, devices can be made available
+ */
+ fast_load = 0;
+ }
+ return -ENXIO;
+ }
+
+ return 0;
+}
+
/*
* Scsi host template for megaraid_sas driver
*/
@@ -1103,6 +1157,7 @@ static struct scsi_host_template megasas
.name = "LSI Logic SAS based MegaRAID driver",
.proc_name = "megaraid_sas",
.slave_configure = megasas_slave_configure,
+ .slave_alloc = megasas_slave_alloc,
.queuecommand = megasas_queue_command,
.eh_device_reset_handler = megasas_reset_device,
.eh_bus_reset_handler = megasas_reset_bus_host,
@@ -2961,20 +3016,6 @@ megasas_mgmt_fw_ioctl(struct megasas_ins
return error;
}

-static struct megasas_instance *megasas_lookup_instance(u16 host_no)
-{
- int i;
-
- for (i = 0; i < megasas_mgmt_info.max_index; i++) {
-
- if ((megasas_mgmt_info.instance[i]) &&
- (megasas_mgmt_info.instance[i]->host->host_no == host_no))
- return megasas_mgmt_info.instance[i];
- }
-
- return NULL;
-}
-
static int megasas_mgmt_ioctl_fw(struct file *file, unsigned long arg)
{
struct megasas_iocpacket __user *user_ioc =