[Intel-gfx] [PATCH v3 3/3] drm/i915/gen9: Fix PCODE polling during SAGV disabling

[Imre Deak]

According to the previous patch, it's possible atm that we call
intel_do_sagv_disable() only once during the 1ms period and time out if
that call fails. As opposed to this the spec says that we need to keep
retrying this request for a 1ms duration, so let's do this similarly to
the CDCLK change notification request.

Cc: Lyude <cpaul at redhat.com>
Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
Cc: Chris Wilson <chris at chris-wilson.co.uk>
Signed-off-by: Imre Deak <imre.deak at intel.com>
---
 drivers/gpu/drm/i915/i915_reg.h |  1 -
 drivers/gpu/drm/i915/intel_pm.c | 33 +++++++--------------------------
 2 files changed, 7 insertions(+), 27 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index f542cbc..c7458b7 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -7434,7 +7434,6 @@ enum {
 #define	  HSW_PCODE_DYNAMIC_DUTY_CYCLE_CONTROL	0x1A
 #define   GEN9_PCODE_SAGV_CONTROL		0x21
 #define     GEN9_SAGV_DISABLE			0x0
-#define     GEN9_SAGV_IS_DISABLED		0x1
 #define     GEN9_SAGV_ENABLE			0x3
 #define   GEN9_PCODE_REQUEST_DONE		0x1
 #define GEN6_PCODE_DATA				_MMIO(0x138128)
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index edd68f3..43b0b40 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -2954,24 +2954,10 @@ intel_enable_sagv(struct drm_i915_private *dev_priv)
 	return 0;
 }
 
-static int
-intel_do_sagv_disable(struct drm_i915_private *dev_priv)
-{
-	int ret;
-	uint32_t temp = GEN9_SAGV_DISABLE;
-
-	ret = sandybridge_pcode_read(dev_priv, GEN9_PCODE_SAGV_CONTROL,
-				     &temp);
-	if (ret)
-		return ret;
-	else
-		return temp & GEN9_SAGV_IS_DISABLED;
-}
-
 int
 intel_disable_sagv(struct drm_i915_private *dev_priv)
 {
-	int ret, result;
+	int ret;
 
 	if (!intel_has_sagv(dev_priv))
 		return 0;
@@ -2981,27 +2967,22 @@ intel_disable_sagv(struct drm_i915_private *dev_priv)
 
 	DRM_DEBUG_KMS("Disabling the SAGV\n");
 	mutex_lock(&dev_priv->rps.hw_lock);
-
 	/* bspec says to keep retrying for at least 1 ms */
-	ret = wait_for(result = intel_do_sagv_disable(dev_priv), 1);
+	ret = skl_pcode_request(dev_priv, GEN9_PCODE_SAGV_CONTROL,
+				GEN9_SAGV_DISABLE);
 	mutex_unlock(&dev_priv->rps.hw_lock);
 
-	if (ret == -ETIMEDOUT) {
-		DRM_ERROR("Request to disable SAGV timed out\n");
-		return -ETIMEDOUT;
-	}
-
 	/*
 	 * Some skl systems, pre-release machines in particular,
 	 * don't actually have an SAGV.
 	 */
-	if (IS_SKYLAKE(dev_priv) && result == -ENXIO) {
+	if (IS_SKYLAKE(dev_priv) && ret == -ENXIO) {
 		DRM_DEBUG_DRIVER("No SAGV found on system, ignoring\n");
 		dev_priv->sagv_status = I915_SAGV_NOT_CONTROLLED;
 		return 0;
-	} else if (result < 0) {
-		DRM_ERROR("Failed to disable the SAGV\n");
-		return result;
+	} else if (ret < 0) {
+		DRM_ERROR("Failed to disable the SAGV (%d)\n", ret);
+		return ret;
 	}
 
 	dev_priv->sagv_status = I915_SAGV_DISABLED;
-- 
2.5.0