ARM: tegra: power: Update Tegra3 auto-hotplug states

Updated Tegra3 auto-hotplug state machine:

- no longer enter down state on LP CPU (there is no down path on LP)
- no longer enter idle state on G CPU (since load distribution between
G cores may change without CPU frequency change, continue polling)
- allow only disabled or idle state to be set via auto-hotplug sysfs
node, and synchronize with cpufreq governor in the latter case

Change-Id: Ibb93ddca852bbe1341fc5c52b0c83c16e9963e9d
Signed-off-by: Alex Frid <afrid@nvidia.com>
Reviewed-on: http://git-master/r/71584
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Wen Yi <wyi@nvidia.com>
Reviewed-by: Diwakar Tundlam <dtundlam@nvidia.com>
Reviewed-by: Krishna Reddy <vdumpa@nvidia.com>

1 files changed, 28 insertions, 26 deletions

diff --git a/arch/arm/mach-tegra/cpu-tegra3.c b/arch/arm/mach-tegra/cpu-tegra3.c
index 6aaa87e36918..78425f4f7643 100644
--- a/arch/arm/mach-tegra/cpu-tegra3.c
+++ b/arch/arm/mach-tegra/cpu-tegra3.c
@@ -143,30 +143,24 @@ static int hp_state_set(const char *arg, const struct kernel_param *kp)
 	mutex_lock(tegra3_cpu_lock);
 
 	old_state = hp_state;
-	ret = param_set_int(arg, kp);
+	ret = param_set_bool(arg, kp);	/* set idle or disabled only */
 
 	if (ret == 0) {
-		switch (hp_state) {
-		case TEGRA_HP_DISABLED:
-			if (old_state != TEGRA_HP_DISABLED)
-				pr_info("Tegra auto-hotplug disabled\n");
-			break;
-		case TEGRA_HP_IDLE:
-		case TEGRA_HP_DOWN:
-		case TEGRA_HP_UP:
+		if ((hp_state == TEGRA_HP_DISABLED) &&
+		    (old_state != TEGRA_HP_DISABLED))
+			pr_info("Tegra auto-hotplug disabled\n");
+		else if (hp_state != TEGRA_HP_DISABLED) {
 			if (old_state == TEGRA_HP_DISABLED) {
-				hp_init_stats();
-				queue_delayed_work(
-					hotplug_wq, &hotplug_work, down_delay);
 				pr_info("Tegra auto-hotplug enabled\n");
+				hp_init_stats();
 			}
-			break;
-		default:
-			pr_warn("%s: unable to set tegra hotplug state %d\n",
-				__func__, hp_state);
-			hp_state = old_state;
+			/* catch-up with governor target speed */
+			tegra_cpu_set_speed_cap(NULL);
 		}
-	}
+	} else
+		pr_warn("%s: unable to set tegra hotplug state %s\n",
+				__func__, arg);
+
 	mutex_unlock(tegra3_cpu_lock);
 	return ret;
 }
@@ -293,7 +287,7 @@ static void tegra_auto_hotplug_work_func(struct work_struct *work)
 
 void tegra_auto_hotplug_governor(unsigned int cpu_freq, bool suspend)
 {
-	unsigned long up_delay;
+	unsigned long up_delay, top_freq, bottom_freq;
 
 	if (!is_g_cluster_present())
 		return;
@@ -303,37 +297,45 @@ void tegra_auto_hotplug_governor(unsigned int cpu_freq, bool suspend)
 		return;
 	}
 
-	up_delay = is_lp_cluster() ? up2g0_delay : up2gn_delay;
+	if (is_lp_cluster()) {
+		up_delay = up2g0_delay;
+		top_freq = idle_top_freq;
+		bottom_freq = 0;
+	} else {
+		up_delay = up2gn_delay;
+		top_freq = idle_bottom_freq;
+		bottom_freq = idle_bottom_freq;
+	}
 
 	switch (hp_state) {
 	case TEGRA_HP_DISABLED:
 		break;
 	case TEGRA_HP_IDLE:
-		if (cpu_freq > idle_top_freq) {
+		if (cpu_freq > top_freq) {
 			hp_state = TEGRA_HP_UP;
 			queue_delayed_work(
 				hotplug_wq, &hotplug_work, up_delay);
-		} else if (cpu_freq <= idle_bottom_freq) {
+		} else if (cpu_freq <= bottom_freq) {
 			hp_state = TEGRA_HP_DOWN;
 			queue_delayed_work(
 				hotplug_wq, &hotplug_work, down_delay);
 		}
 		break;
 	case TEGRA_HP_DOWN:
-		if (cpu_freq > idle_top_freq) {
+		if (cpu_freq > top_freq) {
 			hp_state = TEGRA_HP_UP;
 			queue_delayed_work(
 				hotplug_wq, &hotplug_work, up_delay);
-		} else if (cpu_freq > idle_bottom_freq) {
+		} else if (cpu_freq > bottom_freq) {
 			hp_state = TEGRA_HP_IDLE;
 		}
 		break;
 	case TEGRA_HP_UP:
-		if (cpu_freq <= idle_bottom_freq) {
+		if (cpu_freq <= bottom_freq) {
 			hp_state = TEGRA_HP_DOWN;
 			queue_delayed_work(
 				hotplug_wq, &hotplug_work, down_delay);
-		} else if (cpu_freq <= idle_top_freq) {
+		} else if (cpu_freq <= top_freq) {
 			hp_state = TEGRA_HP_IDLE;
 		}
 		break;