drm/i915: fix the watermark result selection on glk/gen10+

On these platforms we're supposed to unconditonally pick the method 2
result instead of the minimum.

Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181004231600.14101-4-paulo.r.zanoni@intel.com

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 983af46..43fb1f8 100644 (file)
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -4672,15 +4672,24 @@ static int skl_compute_plane_wm(const struct drm_i915_private *dev_priv,
        } else {
                if ((wp->cpp * cstate->base.adjusted_mode.crtc_htotal /
                     wp->dbuf_block_size < 1) &&
-                    (wp->plane_bytes_per_line / wp->dbuf_block_size < 1))
+                    (wp->plane_bytes_per_line / wp->dbuf_block_size < 1)) {
                        selected_result = method2;
-               else if (ddb_allocation >=
-                        fixed16_to_u32_round_up(wp->plane_blocks_per_line))
-                       selected_result = min_fixed16(method1, method2);
-               else if (latency >= wp->linetime_us)
-                       selected_result = min_fixed16(method1, method2);
-               else
+               } else if (ddb_allocation >=
+                        fixed16_to_u32_round_up(wp->plane_blocks_per_line)) {
+                       if (INTEL_GEN(dev_priv) == 9 &&
+                           !IS_GEMINILAKE(dev_priv))
+                               selected_result = min_fixed16(method1, method2);
+                       else
+                               selected_result = method2;
+               } else if (latency >= wp->linetime_us) {
+                       if (INTEL_GEN(dev_priv) == 9 &&
+                           !IS_GEMINILAKE(dev_priv))
+                               selected_result = min_fixed16(method1, method2);
+                       else
+                               selected_result = method2;
+               } else {
                        selected_result = method1;
+               }
        }
 
        res_blocks = fixed16_to_u32_round_up(selected_result) + 1;