[Intel-gfx] [PATCH 17/35] drm/i915: Pull watermark level validity check out

[ville.syrjala at linux.intel.com]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

Refactor the code a bit to split the watermark level validity check into
a separate function.

Also add hack there that allows us to use it even for LP0 watermarks.
ATM we don't pre-compute/check the LP0 watermarks, so we just have to
clamp them to the maximum and hope things work out.

Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/intel_pm.c | 35 +++++++++++++++++++++++++++++++----
 1 file changed, 31 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index a919445..1d63d47 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -2261,6 +2261,36 @@ static uint32_t ilk_compute_fbc_wm(struct hsw_pipe_wm_parameters *params,
 			  params->pri_bytes_per_pixel);
 }
 
+static bool ilk_check_wm(int level,
+			 const struct hsw_wm_maximums *max,
+			 struct hsw_lp_wm_result *result)
+{
+	bool ret;
+
+	result->enable = result->pri_val <= max->pri &&
+			 result->spr_val <= max->spr &&
+			 result->cur_val <= max->cur;
+
+	ret = result->enable;
+
+	/*
+	 * HACK until we can pre-compute everything,
+	 * and thus fail gracefully if LP0 watermarks
+	 * are exceeded...
+	 */
+	if (level == 0 && !result->enable) {
+		result->pri_val = min_t(uint32_t, result->pri_val, max->pri);
+		result->spr_val = min_t(uint32_t, result->spr_val, max->spr);
+		result->cur_val = min_t(uint32_t, result->cur_val, max->cur);
+		result->enable = true;
+		ret = false;
+	}
+
+	DRM_DEBUG_KMS("WM%d: %sabled\n", level, result->enable ? "en" : "dis");
+
+	return ret;
+}
+
 static bool hsw_compute_lp_wm(struct drm_i915_private *dev_priv,
 			      int level, struct hsw_wm_maximums *max,
 			      struct hsw_pipe_wm_parameters *params,
@@ -2293,10 +2323,7 @@ static bool hsw_compute_lp_wm(struct drm_i915_private *dev_priv,
 		result->fbc_enable = true;
 	}
 
-	result->enable = result->pri_val <= max->pri &&
-			 result->spr_val <= max->spr &&
-			 result->cur_val <= max->cur;
-	return result->enable;
+	return ilk_check_wm(level, max, result);
 }
 
 static uint32_t hsw_compute_wm_pipe(struct drm_i915_private *dev_priv,
-- 
1.8.1.5