1 files changed, 146 insertions, 6 deletions

diff --git a/drivers/scsi/megaraid/megaraid_sas.c b/drivers/scsi/megaraid/megaraid_sas.c
index 08c3d4315eb8..499f994f503d 100644
--- a/drivers/scsi/megaraid/megaraid_sas.c
+++ b/drivers/scsi/megaraid/megaraid_sas.c
@@ -47,6 +47,14 @@
 #include <scsi/scsi_host.h>
 #include "megaraid_sas.h"
 
+/*
+ * poll_mode_io:1- schedule complete completion from q cmd
+ */
+static unsigned int poll_mode_io;
+module_param_named(poll_mode_io, poll_mode_io, int, 0);
+MODULE_PARM_DESC(poll_mode_io,
+        "Complete cmds from IO path, (default=0)");
+
 MODULE_LICENSE("GPL");
 MODULE_VERSION(MEGASAS_VERSION);
 MODULE_AUTHOR("megaraidlinux@lsi.com");
@@ -860,6 +868,12 @@ megasas_queue_command(struct scsi_cmnd *scmd, void (*done) (struct scsi_cmnd *))
         atomic_inc(&instance->fw_outstanding);
 
         instance->instancet->fire_cmd(cmd->frame_phys_addr ,cmd->frame_count-1,instance->reg_set);
+        /*
+         * Check if we have pend cmds to be completed
+         */
+        if (poll_mode_io && atomic_read(&instance->fw_outstanding))
+                tasklet_schedule(&instance->isr_tasklet);
+
 
         return 0;
 
@@ -1892,6 +1906,47 @@ fail_fw_init:
 }
 
 /**
+ * megasas_start_timer - Initializes a timer object
+ * @instance:           Adapter soft state
+ * @timer:              timer object to be initialized
+ * @fn:                 timer function
+ * @interval:           time interval between timer function call
+ */
+static inline void
+megasas_start_timer(struct megasas_instance *instance,
+                        struct timer_list *timer,
+                        void *fn, unsigned long interval)
+{
+        init_timer(timer);
+        timer->expires = jiffies + interval;
+        timer->data = (unsigned long)instance;
+        timer->function = fn;
+        add_timer(timer);
+}
+
+/**
+ * megasas_io_completion_timer - Timer fn
+ * @instance_addr:      Address of adapter soft state
+ *
+ * Schedules tasklet for cmd completion
+ * if poll_mode_io is set
+ */
+static void
+megasas_io_completion_timer(unsigned long instance_addr)
+{
+        struct megasas_instance *instance =
+                        (struct megasas_instance *)instance_addr;
+
+        if (atomic_read(&instance->fw_outstanding))
+                tasklet_schedule(&instance->isr_tasklet);
+
+        /* Restart timer */
+        if (poll_mode_io)
+                mod_timer(&instance->io_completion_timer,
+                        jiffies + MEGASAS_COMPLETION_TIMER_INTERVAL);
+}
+
+/**
  * megasas_init_mfi -   Initializes the FW
  * @instance:           Adapter soft state
  *
@@ -2017,8 +2072,14 @@ static int megasas_init_mfi(struct megasas_instance *instance)
         * Setup tasklet for cmd completion
         */
 
-        tasklet_init(&instance->isr_tasklet, megasas_complete_cmd_dpc,
-                        (unsigned long)instance);
+        tasklet_init(&instance->isr_tasklet, megasas_complete_cmd_dpc,
+                (unsigned long)instance);
+
+        /* Initialize the cmd completion timer */
+        if (poll_mode_io)
+                megasas_start_timer(instance, &instance->io_completion_timer,
+                                megasas_io_completion_timer,
+                                MEGASAS_COMPLETION_TIMER_INTERVAL);
         return 0;
 
       fail_fw_init:
@@ -2578,8 +2639,8 @@ static void megasas_shutdown_controller(struct megasas_instance *instance,
 }
 
 /**
- * megasas_suspend -    driver suspend entry point
- * @pdev:               PCI device structure
+ * megasas_suspend -    driver suspend entry point
+ * @pdev:               PCI device structure
  * @state:              PCI power state to suspend routine
  */
 static int __devinit
@@ -2591,6 +2652,9 @@ megasas_suspend(struct pci_dev *pdev, pm_message_t state)
         instance = pci_get_drvdata(pdev);
         host = instance->host;
 
+        if (poll_mode_io)
+                del_timer_sync(&instance->io_completion_timer);
+
         megasas_flush_cache(instance);
         megasas_shutdown_controller(instance, MR_DCMD_HIBERNATE_SHUTDOWN);
         tasklet_kill(&instance->isr_tasklet);
@@ -2677,6 +2741,11 @@ megasas_resume(struct pci_dev *pdev)
         if (megasas_start_aen(instance))
                 printk(KERN_ERR "megasas: Start AEN failed\n");
 
+        /* Initialize the cmd completion timer */
+        if (poll_mode_io)
+                megasas_start_timer(instance, &instance->io_completion_timer,
+                                megasas_io_completion_timer,
+                                MEGASAS_COMPLETION_TIMER_INTERVAL);
         return 0;
 
 fail_irq:
@@ -2715,6 +2784,9 @@ static void megasas_detach_one(struct pci_dev *pdev)
         instance = pci_get_drvdata(pdev);
         host = instance->host;
 
+        if (poll_mode_io)
+                del_timer_sync(&instance->io_completion_timer);
+
         scsi_remove_host(instance->host);
         megasas_flush_cache(instance);
         megasas_shutdown_controller(instance, MR_DCMD_CTRL_SHUTDOWN);
@@ -3188,7 +3260,7 @@ static DRIVER_ATTR(release_date, S_IRUGO, megasas_sysfs_show_release_date,
 static ssize_t
 megasas_sysfs_show_dbg_lvl(struct device_driver *dd, char *buf)
 {
-        return sprintf(buf,"%u",megasas_dbg_lvl);
+        return sprintf(buf, "%u\n", megasas_dbg_lvl);
 }
 
 static ssize_t
@@ -3203,7 +3275,65 @@ megasas_sysfs_set_dbg_lvl(struct device_driver *dd, const char *buf, size_t coun
 }
 
 static DRIVER_ATTR(dbg_lvl, S_IRUGO|S_IWUGO, megasas_sysfs_show_dbg_lvl,
-                   megasas_sysfs_set_dbg_lvl);
+                megasas_sysfs_set_dbg_lvl);
+
+static ssize_t
+megasas_sysfs_show_poll_mode_io(struct device_driver *dd, char *buf)
+{
+        return sprintf(buf, "%u\n", poll_mode_io);
+}
+
+static ssize_t
+megasas_sysfs_set_poll_mode_io(struct device_driver *dd,
+                                const char *buf, size_t count)
+{
+        int retval = count;
+        int tmp = poll_mode_io;
+        int i;
+        struct megasas_instance *instance;
+
+        if (sscanf(buf, "%u", &poll_mode_io) < 1) {
+                printk(KERN_ERR "megasas: could not set poll_mode_io\n");
+                retval = -EINVAL;
+        }
+
+        /*
+         * Check if poll_mode_io is already set or is same as previous value
+         */
+        if ((tmp && poll_mode_io) || (tmp == poll_mode_io))
+                goto out;
+
+        if (poll_mode_io) {
+                /*
+                 * Start timers for all adapters
+                 */
+                for (i = 0; i < megasas_mgmt_info.max_index; i++) {
+                        instance = megasas_mgmt_info.instance[i];
+                        if (instance) {
+                                megasas_start_timer(instance,
+                                        &instance->io_completion_timer,
+                                        megasas_io_completion_timer,
+                                        MEGASAS_COMPLETION_TIMER_INTERVAL);
+                        }
+                }
+        } else {
+                /*
+                 * Delete timers for all adapters
+                 */
+                for (i = 0; i < megasas_mgmt_info.max_index; i++) {
+                        instance = megasas_mgmt_info.instance[i];
+                        if (instance)
+                                del_timer_sync(&instance->io_completion_timer);
+                }
+        }
+
+out:
+        return retval;
+}
+
+static DRIVER_ATTR(poll_mode_io, S_IRUGO|S_IWUGO,
+                megasas_sysfs_show_poll_mode_io,
+                megasas_sysfs_set_poll_mode_io);
 
 /**
  * megasas_init - Driver load entry point
@@ -3254,8 +3384,16 @@ static int __init megasas_init(void)
                                   &driver_attr_dbg_lvl);
         if (rval)
                 goto err_dcf_dbg_lvl;
+        rval = driver_create_file(&megasas_pci_driver.driver,
+                                  &driver_attr_poll_mode_io);
+        if (rval)
+                goto err_dcf_poll_mode_io;
 
         return rval;
+
+err_dcf_poll_mode_io:
+        driver_remove_file(&megasas_pci_driver.driver,
+                           &driver_attr_dbg_lvl);
 err_dcf_dbg_lvl:
         driver_remove_file(&megasas_pci_driver.driver,
                            &driver_attr_release_date);
@@ -3274,6 +3412,8 @@ err_pcidrv:
 static void __exit megasas_exit(void)
 {
         driver_remove_file(&megasas_pci_driver.driver,
+                           &driver_attr_poll_mode_io);
+        driver_remove_file(&megasas_pci_driver.driver,
                            &driver_attr_dbg_lvl);
         driver_remove_file(&megasas_pci_driver.driver,
                            &driver_attr_release_date);