[PATCH 2/3] drm/i915: add enable_ips module option

[Paulo Zanoni <przanoni@gmail.com>]

From: Paulo Zanoni <paulo.r.zanoni@intel.com>

IPS is still enabled by default. Feature requested by the power
management team.

This should also help testing the feature on some early pre-production
hardware where there were relationship problems between IPS and PSR.

Requested-by: Kristen Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
---
 drivers/gpu/drm/i915/i915_drv.c      |    4 ++++
 drivers/gpu/drm/i915/i915_drv.h      |    1 +
 drivers/gpu/drm/i915/intel_display.c |    3 +++
 3 files changed, 8 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index a1a936f..f356304 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -128,6 +128,10 @@ module_param_named(disable_power_well, i915_disable_power_well, int, 0600);
 MODULE_PARM_DESC(disable_power_well,
 		 "Disable the power well when possible (default: false)");
 
+int i915_enable_ips __read_mostly = 1;
+module_param_named(enable_ips, i915_enable_ips, int, 0600);
+MODULE_PARM_DESC(enable_ips, "Enables IPS (default: true)");
+
 static struct drm_driver driver;
 extern int intel_agp_enabled;
 
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 639ec0b..a25669f 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1460,6 +1460,7 @@ extern bool i915_enable_hangcheck __read_mostly;
 extern int i915_enable_ppgtt __read_mostly;
 extern unsigned int i915_preliminary_hw_support __read_mostly;
 extern int i915_disable_power_well __read_mostly;
+extern int i915_enable_ips __read_mostly;
 
 extern int i915_suspend(struct drm_device *dev, pm_message_t state);
 extern int i915_resume(struct drm_device *dev);
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 61e4671..e9129b9 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -3350,6 +3350,9 @@ static bool hsw_crtc_supports_ips(struct drm_crtc *crtc)
 	if (!IS_ULT(dev))
 		return false;
 
+	if (!i915_enable_ips)
+		return false;
+
 	for_each_encoder_on_crtc(dev, crtc, encoder)
 		if (encoder->type == INTEL_OUTPUT_EDP)
 			if (enc_to_dig_port(&encoder->base)->port == PORT_A)
-- 
1.7.10.4