arm: tegra: Fix cpu governor change issue

It fixes the issue where cpu governor change
was inconsistent across platforms.

In T2x, AUTO HOTPLUG is disabled therefore we need
to store/restore gov for all online cpus across
LP0 cycle.

In T3x, AUTO HOTPLUG is enabled therefore storing/restoring
gov for Cpu0 across LP0 cycle. Cpu0 remains online in suspend
and resume.

bug 991081

Change-Id: I167654aa21e4832b3fdc40e3d388a4d3f984632b
Signed-off-by: Puneet Saxena <puneets@nvidia.com>
Reviewed-on: http://git-master/r/105404
Reviewed-by: Simone Willett <swillett@nvidia.com>
Tested-by: Simone Willett <swillett@nvidia.com>

6 files changed, 46 insertions, 36 deletions

diff --git a/arch/arm/mach-tegra/board-enterprise-panel.c b/arch/arm/mach-tegra/board-enterprise-panel.c
index 7043916921d0..97a2294e6f5b 100644
--- a/arch/arm/mach-tegra/board-enterprise-panel.c
+++ b/arch/arm/mach-tegra/board-enterprise-panel.c
@@ -818,9 +818,7 @@ static void enterprise_panel_early_suspend(struct early_suspend *h)
 
 #ifdef CONFIG_TEGRA_CONVSERVATIVE_GOV_ON_EARLYSUPSEND
 	cpufreq_store_default_gov();
-	if (cpufreq_change_gov(cpufreq_conservative_gov))
-		pr_err("Early_suspend: Error changing governor to %s\n",
-				cpufreq_conservative_gov);
+	cpufreq_change_gov(cpufreq_conservative_gov);
 #endif
 }
 
@@ -829,8 +827,7 @@ static void enterprise_panel_late_resume(struct early_suspend *h)
 	unsigned i;
 
 #ifdef CONFIG_TEGRA_CONVSERVATIVE_GOV_ON_EARLYSUPSEND
-	if (cpufreq_restore_default_gov())
-		pr_err("Early_suspend: Unable to restore governor\n");
+	cpufreq_restore_default_gov();
 #endif
 	for (i = 0; i < num_registered_fb; i++)
 		fb_blank(registered_fb[i], FB_BLANK_UNBLANK);
diff --git a/arch/arm/mach-tegra/board-kai-panel.c b/arch/arm/mach-tegra/board-kai-panel.c
index e6ac6dd82846..d98550faf123 100644
--- a/arch/arm/mach-tegra/board-kai-panel.c
+++ b/arch/arm/mach-tegra/board-kai-panel.c
@@ -618,9 +618,7 @@ static void kai_panel_early_suspend(struct early_suspend *h)
 		fb_blank(registered_fb[1], FB_BLANK_NORMAL);
 #ifdef CONFIG_TEGRA_CONVSERVATIVE_GOV_ON_EARLYSUPSEND
 	cpufreq_store_default_gov();
-	if (cpufreq_change_gov(cpufreq_conservative_gov))
-		pr_err("Early_suspend: Error changing governor to %s\n",
-				cpufreq_conservative_gov);
+	cpufreq_change_gov(cpufreq_conservative_gov);
 #endif
 }
 
@@ -628,8 +626,7 @@ static void kai_panel_late_resume(struct early_suspend *h)
 {
 	unsigned i;
 #ifdef CONFIG_TEGRA_CONVSERVATIVE_GOV_ON_EARLYSUPSEND
-	if (cpufreq_restore_default_gov())
-		pr_err("Early_suspend: Unable to restore governor\n");
+	cpufreq_restore_default_gov();
 #endif
 	for (i = 0; i < num_registered_fb; i++)
 		fb_blank(registered_fb[i], FB_BLANK_UNBLANK);
diff --git a/arch/arm/mach-tegra/board-ventana-panel.c b/arch/arm/mach-tegra/board-ventana-panel.c
index a9e7a67f2bb1..0013e36d38a6 100644
--- a/arch/arm/mach-tegra/board-ventana-panel.c
+++ b/arch/arm/mach-tegra/board-ventana-panel.c
@@ -367,9 +367,7 @@ static void ventana_panel_early_suspend(struct early_suspend *h)
 		fb_blank(registered_fb[1], FB_BLANK_NORMAL);
 #ifdef CONFIG_TEGRA_CONVSERVATIVE_GOV_ON_EARLYSUPSEND
 	cpufreq_store_default_gov();
-	if (cpufreq_change_gov(cpufreq_conservative_gov))
-		pr_err("Early_suspend: Error changing governor to %s\n",
-				cpufreq_conservative_gov);
+	cpufreq_change_gov(cpufreq_conservative_gov);
 #endif
 }
 
@@ -377,8 +375,7 @@ static void ventana_panel_late_resume(struct early_suspend *h)
 {
 	unsigned i;
 #ifdef CONFIG_TEGRA_CONVSERVATIVE_GOV_ON_EARLYSUPSEND
-	if (cpufreq_restore_default_gov())
-		pr_err("Early_suspend: Unable to restore governor\n");
+	cpufreq_restore_default_gov();
 #endif
 	for (i = 0; i < num_registered_fb; i++)
 		fb_blank(registered_fb[i], FB_BLANK_UNBLANK);
diff --git a/arch/arm/mach-tegra/board-whistler-panel.c b/arch/arm/mach-tegra/board-whistler-panel.c
index 3510f9468394..df8b2859e81c 100644
--- a/arch/arm/mach-tegra/board-whistler-panel.c
+++ b/arch/arm/mach-tegra/board-whistler-panel.c
@@ -320,9 +320,7 @@ static void whistler_panel_early_suspend(struct early_suspend *h)
 
 #ifdef CONFIG_TEGRA_CONVSERVATIVE_GOV_ON_EARLYSUPSEND
 	cpufreq_store_default_gov();
-	if (cpufreq_change_gov(cpufreq_conservative_gov))
-		pr_err("Early_suspend: Error changing governor to %s\n",
-				cpufreq_conservative_gov);
+	cpufreq_change_gov(cpufreq_conservative_gov);
 #endif
 }
 
@@ -331,8 +329,7 @@ static void whistler_panel_late_resume(struct early_suspend *h)
 	unsigned i;
 
 #ifdef CONFIG_TEGRA_CONVSERVATIVE_GOV_ON_EARLYSUPSEND
-	if (cpufreq_restore_default_gov())
-		pr_err("Early_suspend: Unable to restore governor\n");
+	cpufreq_restore_default_gov();
 #endif
 
 	for (i = 0; i < num_registered_fb; i++)
diff --git a/arch/arm/mach-tegra/board.h b/arch/arm/mach-tegra/board.h
index 63095ce9336a..7c081fad642a 100644
--- a/arch/arm/mach-tegra/board.h
+++ b/arch/arm/mach-tegra/board.h
@@ -164,8 +164,8 @@ extern char cpufreq_default_gov[][MAX_GOV_NAME_LEN];
 extern char *cpufreq_conservative_gov;
 
 void cpufreq_store_default_gov(void);
-int cpufreq_restore_default_gov(void);
-int cpufreq_change_gov(char *target_gov);
+void cpufreq_restore_default_gov(void);
+void cpufreq_change_gov(char *target_gov);
 #endif
 
 int get_core_edp(void);
diff --git a/arch/arm/mach-tegra/common.c b/arch/arm/mach-tegra/common.c
index 2986f1cf61ac..59b4f954ee79 100644
--- a/arch/arm/mach-tegra/common.c
+++ b/arch/arm/mach-tegra/common.c
@@ -959,38 +959,61 @@ char *cpufreq_conservative_gov = "conservative";
 
 void cpufreq_store_default_gov(void)
 {
-	unsigned int cpu;
+	unsigned int cpu = 0;
 	struct cpufreq_policy *policy;
 
-	for (cpu = 0; cpu < CONFIG_NR_CPUS; cpu++) {
+#ifndef CONFIG_TEGRA_AUTO_HOTPLUG
+	for_each_online_cpu(cpu)
+#endif
+	{
 		policy = cpufreq_cpu_get(cpu);
-		if (policy) {
+		if (policy && policy->governor) {
 			sprintf(cpufreq_default_gov[cpu], "%s",
 					policy->governor->name);
 			cpufreq_cpu_put(policy);
+		} else {
+			/* No policy or no gov set for this
+			 * online cpu. If we are here, require
+			 * serious debugging hence setting
+			 * as pr_error.
+			 */
+			pr_err("No gov or No policy for online cpu:%d,"
+					, cpu);
 		}
 	}
 }
 
-int cpufreq_change_gov(char *target_gov)
+void cpufreq_change_gov(char *target_gov)
 {
-	unsigned int cpu = 0, ret = -EINVAL;
+	int ret = -EINVAL;
+	unsigned int cpu = 0;
 
 #ifndef CONFIG_TEGRA_AUTO_HOTPLUG
 	for_each_online_cpu(cpu)
 #endif
-	ret = cpufreq_set_gov(target_gov, cpu);
-
-	return ret;
+	{
+		ret = cpufreq_set_gov(target_gov, cpu);
+		if (ret < 0)
+			/* Unable to set gov for the online cpu.
+			 * If it happens, needs to debug.
+			 */
+			pr_info("Unable to set gov:%s for online cpu:%d,"
+				, cpufreq_default_gov[cpu]
+					, cpu);
+	}
 }
 
-int cpufreq_restore_default_gov(void)
+void cpufreq_restore_default_gov(void)
 {
-	int ret = 0;
-	unsigned int cpu;
+	int ret = -EINVAL;
+	unsigned int cpu = 0;
 
-	for (cpu = 0; cpu < CONFIG_NR_CPUS; cpu++) {
-		if (strlen((const char *)&cpufreq_default_gov[cpu])) {
+#ifndef CONFIG_TEGRA_AUTO_HOTPLUG
+	for_each_online_cpu(cpu)
+#endif
+	{
+		if (&cpufreq_default_gov[cpu] &&
+			strlen((const char *)&cpufreq_default_gov[cpu])) {
 			ret = cpufreq_set_gov(cpufreq_default_gov[cpu], cpu);
 			if (ret < 0)
 				/* Unable to restore gov for the cpu as
@@ -1003,6 +1026,5 @@ int cpufreq_restore_default_gov(void)
 		}
 		cpufreq_default_gov[cpu][0] = '\0';
 	}
-	return ret;
 }
 #endif /* CONFIG_TEGRA_CONVSERVATIVE_GOV_ON_EARLYSUPSEND */