drm/i915: enable self-refresh on 965

Need to calculate the SR watermark and enable it.

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Eric Anholt <eric@anholt.net>

1 files changed, 28 insertions, 4 deletions

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index e4221b8844ce..43af081328fe 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -2551,15 +2551,39 @@ static void g4x_update_wm(struct drm_device *dev,  int planea_clock,
                    (cursor_sr << DSPFW_CURSOR_SR_SHIFT));
 }
 
-static void i965_update_wm(struct drm_device *dev, int unused, int unused2,
-                           int unused3, int unused4)
+static void i965_update_wm(struct drm_device *dev, int planea_clock,
+                           int planeb_clock, int sr_hdisplay, int pixel_size)
 {
         struct drm_i915_private *dev_priv = dev->dev_private;
+        unsigned long line_time_us;
+        int sr_clock, sr_entries, srwm = 1;
+
+        /* Calc sr entries for one plane configs */
+        if (sr_hdisplay && (!planea_clock || !planeb_clock)) {
+                /* self-refresh has much higher latency */
+                const static int sr_latency_ns = 12000;
+
+                sr_clock = planea_clock ? planea_clock : planeb_clock;
+                line_time_us = ((sr_hdisplay * 1000) / sr_clock);
+
+                /* Use ns/us then divide to preserve precision */
+                sr_entries = (((sr_latency_ns / line_time_us) + 1) *
+                              pixel_size * sr_hdisplay) / 1000;
+                sr_entries = roundup(sr_entries / I915_FIFO_LINE_SIZE, 1);
+                DRM_DEBUG("self-refresh entries: %d\n", sr_entries);
+                srwm = I945_FIFO_SIZE - sr_entries;
+                if (srwm < 0)
+                        srwm = 1;
+                srwm &= 0x3f;
+                I915_WRITE(FW_BLC_SELF, FW_BLC_SELF_EN);
+        }
 
-        DRM_DEBUG_KMS("Setting FIFO watermarks - A: 8, B: 8, C: 8, SR 8\n");
+        DRM_DEBUG_KMS("Setting FIFO watermarks - A: 8, B: 8, C: 8, SR %d\n",
+                      srwm);
 
         /* 965 has limitations... */
-        I915_WRITE(DSPFW1, (8 << 16) | (8 << 8) | (8 << 0));
+        I915_WRITE(DSPFW1, (srwm << DSPFW_SR_SHIFT) | (8 << 16) | (8 << 8) |
+                   (8 << 0));
         I915_WRITE(DSPFW2, (8 << 8) | (8 << 0));
 }