[PATCH v2 3/3] drm/i915: Add boot paramter to control rps boost at boot time.

[deepak.s@linux.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.

v2: Addressed rps default comment (Jani)

Signed-off-by: Deepak S <deepak.s@linux.intel.com>
---
 drivers/gpu/drm/i915/i915_drv.h    |  1 +
 drivers/gpu/drm/i915/i915_gem.c    | 16 +++++++++++++++-
 drivers/gpu/drm/i915/i915_params.c |  5 +++++
 3 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 607042b..7808319 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2106,6 +2106,7 @@ struct i915_params {
 	int panel_use_ssc;
 	int vbt_sdvo_panel_type;
 	int enable_rc6;
+	int enable_rps_boost;
 	int enable_fbc;
 	int enable_ppgtt;
 	int enable_psr;
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 92b0b41..23a4700 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1002,6 +1002,17 @@ 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
@@ -1042,8 +1053,11 @@ static int __wait_seqno(struct intel_ring_buffer *ring, u32 seqno,
 
 	timeout_expire = timeout ? jiffies + timespec_to_jiffies_timeout(timeout) : 0;
 
-	if (INTEL_INFO(dev)->gen >= 6 && can_wait_boost(file_priv)) {
+	if (INTEL_INFO(dev)->gen >= 6 && can_wait_boost(file_priv) && 
+			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 a66ffb6..2d207e3 100644
--- a/drivers/gpu/drm/i915/i915_params.c
+++ b/drivers/gpu/drm/i915/i915_params.c
@@ -34,6 +34,7 @@ struct i915_params i915 __read_mostly = {
 	.panel_use_ssc = -1,
 	.vbt_sdvo_panel_type = -1,
 	.enable_rc6 = -1,
+	.enable_rps_boost = 1,
 	.enable_fbc = -1,
 	.enable_hangcheck = true,
 	.enable_ppgtt = -1,
@@ -78,6 +79,10 @@ MODULE_PARM_DESC(enable_rc6,
 	"For example, 3 would enable rc6 and deep rc6, and 7 would enable everything. "
 	"default: -1 (use per-chip default)");
 
+module_param_named(enable_rps_boost, i915.enable_rps_boost, int, 0600);
+MODULE_PARM_DESC(enable_rps_boost,
+		"Enable/Disable boost RPS frequency (default: enabled (1))");
+
 module_param_named(enable_fbc, i915.enable_fbc, int, 0600);
 MODULE_PARM_DESC(enable_fbc,
 	"Enable frame buffer compression for power savings "
-- 
1.8.4.2