[Intel-gfx] [PATCH] drm/i915: Introduce sw_turbo parameter.

[Rodrigo Vivi]

bdw_sw_turbo is been enabled unconditionally and it is causing gpu to be busted.
GT freq stays on max value even when it is on idle or with screen off.

And if this isn't actually the case it is at least breaking the current rps API.
So let's let it disabled by default for now until it is properly adressing the tests.

References: https://bugs.freedesktop.org/show_bug.cgi?id=77869
Cc: Daisy Sun <daisy.sun at intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi at intel.com>
---
 drivers/gpu/drm/i915/i915_drv.h    | 1 +
 drivers/gpu/drm/i915/i915_params.c | 6 ++++++
 drivers/gpu/drm/i915/intel_pm.c    | 2 +-
 3 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index e845a81..159ddd8 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2215,6 +2215,7 @@ struct i915_params {
 	int lvds_channel_mode;
 	int panel_use_ssc;
 	int vbt_sdvo_panel_type;
+	int sw_turbo;
 	int enable_rc6;
 	int enable_fbc;
 	int enable_ppgtt;
diff --git a/drivers/gpu/drm/i915/i915_params.c b/drivers/gpu/drm/i915/i915_params.c
index 139f490..1cd587c 100644
--- a/drivers/gpu/drm/i915/i915_params.c
+++ b/drivers/gpu/drm/i915/i915_params.c
@@ -33,6 +33,7 @@ struct i915_params i915 __read_mostly = {
 	.lvds_channel_mode = 0,
 	.panel_use_ssc = -1,
 	.vbt_sdvo_panel_type = -1,
+	.sw_turbo = 0,
 	.enable_rc6 = -1,
 	.enable_fbc = -1,
 	.enable_execlists = 0,
@@ -72,6 +73,11 @@ MODULE_PARM_DESC(semaphores,
 	"Use semaphores for inter-ring sync "
 	"(default: -1 (use per-chip defaults))");
 
+module_param_named(sw_turbo, i915.sw_turbo, int, 0400);
+MODULE_PARM_DESC(sw_turbo,
+	"Use SW Turbo. Currently available only on Broadwell"
+	"(default: 0 (disabled))");
+
 module_param_named(enable_rc6, i915.enable_rc6, int, 0400);
 MODULE_PARM_DESC(enable_rc6,
 	"Enable power-saving render C-state 6. "
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 49af81f..d51b17d 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -3789,7 +3789,7 @@ static void gen8_enable_rps(struct drm_device *dev)
 	int unused;
 
 	/* Use software Turbo for BDW */
-	dev_priv->rps.is_bdw_sw_turbo = IS_BROADWELL(dev);
+	dev_priv->rps.is_bdw_sw_turbo = IS_BROADWELL(dev) && i915.sw_turbo;
 
 	/* 1a: Software RC state - RC0 */
 	I915_WRITE(GEN6_RC_STATE, 0);
-- 
1.9.3