7 files changed, 30 insertions, 36 deletions

diff --git a/drivers/gpu/nvgpu/common/linux/debug.c b/drivers/gpu/nvgpu/common/linux/debug.c
index ee93a901..8738f3e7 100644
--- a/drivers/gpu/nvgpu/common/linux/debug.c
+++ b/drivers/gpu/nvgpu/common/linux/debug.c
@@ -267,9 +267,6 @@ static int gk20a_railgating_debugfs_init(struct gk20a *g)
         struct nvgpu_os_linux *l = nvgpu_os_linux_from_gk20a(g);
         struct dentry *d;
 
-        if (!g->can_railgate)
-                return 0;
-
         d = debugfs_create_file(
                 "railgate_residency", S_IRUGO|S_IWUSR, l->debugfs, g,
                                                 &railgate_residency_fops);
diff --git a/drivers/gpu/nvgpu/common/linux/driver_common.c b/drivers/gpu/nvgpu/common/linux/driver_common.c
index 015046dd..2475912a 100644
--- a/drivers/gpu/nvgpu/common/linux/driver_common.c
+++ b/drivers/gpu/nvgpu/common/linux/driver_common.c
@@ -168,8 +168,12 @@ static void nvgpu_init_pm_vars(struct gk20a *g)
         g->ptimer_src_freq = platform->ptimer_src_freq;
         g->support_pmu = support_gk20a_pmu(dev_from_gk20a(g));
         g->can_railgate = platform->can_railgate_init;
-        g->railgate_delay = platform->railgate_delay_init;
         g->ldiv_slowdown_factor = platform->ldiv_slowdown_factor_init;
+        /* if default delay is not set, set default delay to 500msec */
+        if (platform->railgate_delay_init)
+                g->railgate_delay = platform->railgate_delay_init;
+        else
+                g->railgate_delay = NVGPU_DEFAULT_RAILGATE_IDLE_TIMEOUT;
         __nvgpu_set_enabled(g, NVGPU_PMU_PERFMON, platform->enable_perfmon);
 
         /* set default values to aelpg parameters */
diff --git a/drivers/gpu/nvgpu/common/linux/module.c b/drivers/gpu/nvgpu/common/linux/module.c
index 86abd36b..a7289b66 100644
--- a/drivers/gpu/nvgpu/common/linux/module.c
+++ b/drivers/gpu/nvgpu/common/linux/module.c
@@ -458,10 +458,10 @@ int __gk20a_do_idle(struct gk20a *g, bool force_reset)
          * If User disables rail gating, we take one more
          * extra refcount
          */
-        if (g->user_railgate_disabled)
-                target_ref_cnt = 2;
-        else
+        if (g->can_railgate)
                 target_ref_cnt = 1;
+        else
+                target_ref_cnt = 2;
         nvgpu_mutex_acquire(&platform->railgate_lock);
 
         nvgpu_timeout_init(g, &timeout, GK20A_WAIT_FOR_IDLE_MS,
@@ -964,7 +964,7 @@ static int gk20a_pm_suspend(struct device *dev)
         struct gk20a_platform *platform = dev_get_drvdata(dev);
         struct gk20a *g = get_gk20a(dev);
         int ret = 0;
-        int idle_usage_count = g->user_railgate_disabled ? 1 : 0;
+        int idle_usage_count = 0;
 
         if (!g->power_on) {
                 if (!pm_runtime_enabled(dev))
@@ -1020,23 +1020,19 @@ static int gk20a_pm_init(struct device *dev)
 
         nvgpu_log_fn(g, " ");
 
-        /* Initialise pm runtime */
-        if (g->railgate_delay) {
+        /*
+         * Initialise pm runtime. For railgate disable
+         * case, set autosuspend delay to negative which
+         * will suspend runtime pm
+         */
+        if (g->railgate_delay && g->can_railgate)
                 pm_runtime_set_autosuspend_delay(dev,
                                  g->railgate_delay);
-                pm_runtime_use_autosuspend(dev);
-        }
+        else
+                pm_runtime_set_autosuspend_delay(dev, -1);
 
-        if (g->can_railgate) {
-                pm_runtime_enable(dev);
-                if (!pm_runtime_enabled(dev))
-                        gk20a_pm_unrailgate(dev);
-                else
-                        gk20a_pm_railgate(dev);
-        } else {
-                __pm_runtime_disable(dev, false);
-                gk20a_pm_unrailgate(dev);
-        }
+        pm_runtime_use_autosuspend(dev);
+        pm_runtime_enable(dev);
 
         return err;
 }
diff --git a/drivers/gpu/nvgpu/common/linux/sysfs.c b/drivers/gpu/nvgpu/common/linux/sysfs.c
index e425e153..7a887beb 100644
--- a/drivers/gpu/nvgpu/common/linux/sysfs.c
+++ b/drivers/gpu/nvgpu/common/linux/sysfs.c
@@ -305,24 +305,23 @@ static ssize_t railgate_enable_store(struct device *dev,
         unsigned long railgate_enable = 0;
         /* dev is guaranteed to be valid here. Ok to de-reference */
         struct gk20a *g = get_gk20a(dev);
-        int err = 0;
+        int err;
 
         if (kstrtoul(buf, 10, &railgate_enable) < 0)
                 return -EINVAL;
 
         if (railgate_enable && !g->can_railgate) {
-                /* release extra ref count */
-                gk20a_idle(g);
                 g->can_railgate = true;
-                g->user_railgate_disabled = false;
+                pm_runtime_set_autosuspend_delay(dev, g->railgate_delay);
         } else if (railgate_enable == 0 && g->can_railgate) {
-                /* take extra ref count */
-                err = gk20a_busy(g);
-                if (err)
-                        return err;
                 g->can_railgate = false;
-                g->user_railgate_disabled = true;
+                pm_runtime_set_autosuspend_delay(dev, -1);
         }
+        /* wake-up system to make rail-gating setting effective */
+        err = gk20a_busy(g);
+        if (err)
+                return err;
+        gk20a_idle(g);
 
         nvgpu_info(g, "railgate is %s.", g->can_railgate ?
                 "enabled" : "disabled");
diff --git a/drivers/gpu/nvgpu/gk20a/gk20a.c b/drivers/gpu/nvgpu/gk20a/gk20a.c
index 9ce2ef53..b502ef02 100644
--- a/drivers/gpu/nvgpu/gk20a/gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/gk20a.c
@@ -370,9 +370,6 @@ int gk20a_wait_for_idle(struct gk20a *g)
         if (!g)
                 return -ENODEV;
 
-        if (g->user_railgate_disabled)
-                target_usage_count = 1;
-
         while ((nvgpu_atomic_read(&g->usage_count) != target_usage_count)
                         && (wait_length-- >= 0))
                 nvgpu_msleep(20);
diff --git a/drivers/gpu/nvgpu/gk20a/gk20a.h b/drivers/gpu/nvgpu/gk20a/gk20a.h
index 07ff28f6..77e6e759 100644
--- a/drivers/gpu/nvgpu/gk20a/gk20a.h
+++ b/drivers/gpu/nvgpu/gk20a/gk20a.h
@@ -1358,7 +1358,6 @@ struct gk20a {
         u32 ptimer_src_freq;
 
         bool can_railgate;
-        bool user_railgate_disabled;
         int railgate_delay;
         u8 ldiv_slowdown_factor;
         unsigned int aggressive_sync_destroy_thresh;
diff --git a/drivers/gpu/nvgpu/include/nvgpu/defaults.h b/drivers/gpu/nvgpu/include/nvgpu/defaults.h
index 2d7a42b1..cae380a7 100644
--- a/drivers/gpu/nvgpu/include/nvgpu/defaults.h
+++ b/drivers/gpu/nvgpu/include/nvgpu/defaults.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017, NVIDIA CORPORATION.  All rights reserved.
+ * Copyright (c) 2017-2018, NVIDIA CORPORATION.  All rights reserved.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the "Software"),
@@ -28,4 +28,6 @@
  */
 #define NVGPU_DEFAULT_GR_IDLE_TIMEOUT   3000
 
+#define NVGPU_DEFAULT_RAILGATE_IDLE_TIMEOUT 500
+
 #endif