drm/i915: Add SNB/IVB support to intel_read_wm_latency

SNB and IVB have slightly a different way to read out the
watermark latency values.

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

1 files changed, 7 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index b6430bacc7dc..da1b64121611 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -2365,6 +2365,13 @@ static void intel_read_wm_latency(struct drm_device *dev, uint16_t wm[5])
                 wm[2] = (sskpd >> 12) & 0xFF;
                 wm[3] = (sskpd >> 20) & 0x1FF;
                 wm[4] = (sskpd >> 32) & 0x1FF;
+        } else if (INTEL_INFO(dev)->gen >= 6) {
+                uint32_t sskpd = I915_READ(MCH_SSKPD);
+
+                wm[0] = (sskpd >> SSKPD_WM0_SHIFT) & SSKPD_WM_MASK;
+                wm[1] = (sskpd >> SSKPD_WM1_SHIFT) & SSKPD_WM_MASK;
+                wm[2] = (sskpd >> SSKPD_WM2_SHIFT) & SSKPD_WM_MASK;
+                wm[3] = (sskpd >> SSKPD_WM3_SHIFT) & SSKPD_WM_MASK;
         }
 }