[PATCH] drm/i915: Add boot paramter to control rps boost at boot time.

[deepak.s@intel.com]

From: Deepak S <deepak.s@intel.com>

We are adding a module paramter to control rps boost. By default, we
enable the boost for better performace. Based on the need (perf/power)
we can either enable/disable.

Signed-off-by: Deepak S <deepak.s@intel.com>
---
 drivers/gpu/drm/i915/i915_drv.h    |  1 +
 drivers/gpu/drm/i915/i915_gem.c    | 15 ++++++++++++++-
 drivers/gpu/drm/i915/i915_params.c |  8 ++++++++
 3 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 2baeeef..398b101 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1963,6 +1963,7 @@ struct i915_params {
 	int panel_use_ssc;
 	int vbt_sdvo_panel_type;
 	int enable_rc6;
+	int enable_rps_boost;
 	int enable_fbc;
 	bool enable_hangcheck;
 	int enable_ppgtt;
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index a8a069f..1478ea6 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -990,6 +990,17 @@ static bool can_wait_boost(struct drm_i915_file_private *file_priv)
 	return !atomic_xchg(&file_priv->rps_wait_boost, true);
 }
 
+static int  intel_enable_rps_boost(struct drm_device *dev)
+{
+	/* No RPS Boost before Ironlake */
+	if (INTEL_INFO(dev)->gen < 6)
+		return 0;
+
+	/* Respect the kernel parameter if it is set */
+	return i915.enable_rps_boost;
+
+}
+
 /**
  * __wait_seqno - wait until execution of seqno has finished
  * @ring: the ring expected to report seqno
@@ -1030,7 +1041,9 @@ static int __wait_seqno(struct intel_ring_buffer *ring, u32 seqno,
 	timeout_expire = timeout ? jiffies + timespec_to_jiffies_timeout(timeout) : 0;
 
 	if (dev_priv->info->gen >= 6 && can_wait_boost(file_priv)) {
-		gen6_rps_boost(dev_priv);
+		if (intel_enable_rps_boost(ring->dev))
+			gen6_rps_boost(dev_priv);
+
 		if (file_priv)
 			mod_delayed_work(dev_priv->wq,
 					 &file_priv->mm.idle_work,
diff --git a/drivers/gpu/drm/i915/i915_params.c b/drivers/gpu/drm/i915/i915_params.c
index c743057..a19bd7d 100644
--- a/drivers/gpu/drm/i915/i915_params.c
+++ b/drivers/gpu/drm/i915/i915_params.c
@@ -47,6 +47,7 @@ struct i915_params i915 __read_mostly = {
 	.prefault_disable = 0,
 	.reset = true,
 	.invert_brightness = 0,
+	.enable_rps_boost = 1,
 };
 
 module_param_named(modeset, i915.modeset, int, 0400);
@@ -153,3 +154,10 @@ MODULE_PARM_DESC(invert_brightness,
 	"report PCI device ID, subsystem vendor and subsystem device ID "
 	"to dri-devel@lists.freedesktop.org, if your machine needs it. "
 	"It will then be included in an upcoming module version.");
+
+module_param_named(enable_rps_boost, i915.enable_rps_boost, int, 0600);
+MODULE_PARM_DESC(enable_rps_boost,
+		"Enable/Disable boost RPS frequency (default: true)");
+
+
+
-- 
1.8.5.2