drm/i915: properly set HSW WM_LP watermarks

We were previously only setting the WM_PIPE registers, now we are
setting the LP watermark registers. This should allow deeper PC
states, resulting in power savings.

We're only using 1/2 data buffer partitioning for now.

v2: Merge both hsw_compute_pri_wm_* functions (Ville)
v3: - Simplify hsw_compute_wm_results (Ville)
    - Rebase due to changes on the previous patch
v4: Unconfuse wm_lp/level (Ville)

Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 4 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 19021bd8b030..e00422128a0a 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -3100,6 +3100,10 @@
 #define WM3S_LP_IVB             0x45128
 #define  WM1S_LP_EN             (1<<31)
 
+#define HSW_WM_LP_VAL(lat, fbc, pri, cur) \
+        (WM3_LP_EN | ((lat) << WM1_LP_LATENCY_SHIFT) | \
+         ((fbc) << WM1_LP_FBC_SHIFT) | ((pri) << WM1_LP_SR_SHIFT) | (cur))
+
 /* Memory latency timer register */
 #define MLTR_ILK                0x11222
 #define  MLTR_WM1_SHIFT         0