Add support for changing cdclk frequency during runtime on BDW. The
procedure is quite a bit different on BDW from the one on HSW, so
add a separate function for it.

Also with IPS enabled the actual pixel rate mustn't exceed 95% of cdclk,
so take that into account when computing the max pixel rate.

v2: Grab rps.hw_lock around sandybridge_pcode_write()
v3: Rebase due to power well vs. .global_resources() reordering

Signed-off-by: Ville Syrjälä <ville.syrj...@linux.intel.com>

v4: Rebased to the latest

Signed-off-by: Mika Kahola <mika.kah...@intel.com>
---
 drivers/gpu/drm/i915/i915_reg.h      |   1 +
 drivers/gpu/drm/i915/intel_display.c | 138 ++++++++++++++++++++++++++++++-----
 2 files changed, 122 insertions(+), 17 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 74ff995..782d471 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -6411,6 +6411,7 @@ enum skl_disp_power_wells {
 #define   GEN6_ENCODE_RC6_VID(mv)              (((mv) - 245) / 5)
 #define   GEN6_DECODE_RC6_VID(vids)            (((vids) * 5) + 245)
 #define   HSW_PCODE_DE_WRITE_FREQ_REQ          0x17
+#define   BDW_PCODE_DISPLAY_FREQ_CHANGE_REQ    0x18
 #define   DISPLAY_IPS_CONTROL                  0x19
 #define          HSW_PCODE_DYNAMIC_DUTY_CYCLE_CONTROL  0x1A
 #define GEN6_PCODE_DATA                                0x138128
diff --git a/drivers/gpu/drm/i915/intel_display.c 
b/drivers/gpu/drm/i915/intel_display.c
index 35489cd..09f3518 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -5214,7 +5214,22 @@ static void intel_update_max_cdclk(struct drm_device 
*dev)
 {
        struct drm_i915_private *dev_priv = dev->dev_private;
 
-       if (IS_HASWELL(dev)) {
+       if (IS_BROADWELL(dev))  {
+               /*
+                * FIXME with extra cooling we can allow
+                * 540 MHz for ULX and 675 Mhz for ULT.
+                * How can we know if extra cooling is
+                * available? PCI ID, VTB, something else?
+                */
+               if (I915_READ(FUSE_STRAP) & HSW_CDCLK_LIMIT)
+                       dev_priv->max_cdclk_freq = 450000;
+               else if (IS_BDW_ULX(dev))
+                       dev_priv->max_cdclk_freq = 450000;
+               else if (IS_BDW_ULT(dev))
+                       dev_priv->max_cdclk_freq = 540000;
+               else
+                       dev_priv->max_cdclk_freq = 675000;
+       } else if (IS_HASWELL(dev)) {
                if (I915_READ(FUSE_STRAP) & HSW_CDCLK_LIMIT)
                        dev_priv->max_cdclk_freq = 450000;
                else if (IS_HSW_ULX(dev))
@@ -6092,13 +6107,11 @@ static bool pipe_config_supports_ips(struct 
drm_i915_private *dev_priv,
                return true;
 
        /*
-        * FIXME if we compare against max we should then
-        * increase the cdclk frequency when the current
-        * value is too low. The other option is to compare
-        * against the cdclk frequency we're going have post
-        * modeset (ie. one we computed using other constraints).
-        * Need to measure whether using a lower cdclk w/o IPS
-        * is better or worse than a higher cdclk w/ IPS.
+        * We compare against max which means we must take
+        * the increased cdclk requirement into account when
+        * calculating the new cdclk.
+        *
+        * Should measure whether using a lower cdclk w/o IPS
         */
        return ilk_pipe_pixel_rate(pipe_config) <=
                dev_priv->max_cdclk_freq * 95 / 100;
@@ -9082,9 +9095,18 @@ static int ilk_max_pixel_rate(struct drm_i915_private 
*dev_priv)
        int max_pixel_rate = 0;
 
        for_each_intel_crtc(dev, crtc) {
-               if (crtc->new_enabled)
-                       max_pixel_rate = max((int)max_pixel_rate,
-                                            
(int)ilk_pipe_pixel_rate(crtc->config));
+               int pixel_rate;
+
+               if (!crtc->new_enabled)
+                       continue;
+
+               pixel_rate = ilk_pipe_pixel_rate(crtc->config);
+
+               /* pixel rate mustn't exceed 95% of cdclk with IPS on BDW */
+               if (IS_BROADWELL(dev) && crtc->config->ips_enabled)
+                       pixel_rate = DIV_ROUND_UP(pixel_rate * 100, 95);
+
+               max_pixel_rate = max(max_pixel_rate, pixel_rate);
        }
 
        return max_pixel_rate;
@@ -9099,7 +9121,9 @@ static int haswell_calc_cdclk(struct drm_i915_private 
*dev_priv,
         * FIXME should also account for plane ratio
         * once 64bpp pixel formats are supported.
         */
-       if (max_pixel_rate > 450000)
+       if (max_pixel_rate > 540000)
+               cdclk = 675000;
+       else if (max_pixel_rate > 450000)
                cdclk = 540000;
        else if (max_pixel_rate > 337500 || !IS_HSW_ULX(dev_priv))
                cdclk = 450000;
@@ -9164,6 +9188,83 @@ static void haswell_set_cdclk(struct drm_device *dev, 
int cdclk)
             cdclk, dev_priv->cdclk_freq);
 }
 
+static void broadwell_set_cdclk(struct drm_device *dev, int cdclk)
+{
+       struct drm_i915_private *dev_priv = dev->dev_private;
+       uint32_t val, data;
+       int ret;
+
+       if (WARN((I915_READ(LCPLL_CTL) &
+                 (LCPLL_PLL_DISABLE | LCPLL_PLL_LOCK |
+                  LCPLL_CD_CLOCK_DISABLE | LCPLL_ROOT_CD_CLOCK_DISABLE |
+                  LCPLL_CD2X_CLOCK_DISABLE | LCPLL_POWER_DOWN_ALLOW |
+                  LCPLL_CD_SOURCE_FCLK)) != LCPLL_PLL_LOCK,
+                "trying to change cdclk frequency with cdclk not enabled\n"))
+               return;
+
+       mutex_lock(&dev_priv->rps.hw_lock);
+       ret = sandybridge_pcode_write(dev_priv,
+                                     BDW_PCODE_DISPLAY_FREQ_CHANGE_REQ, 0x0);
+       mutex_unlock(&dev_priv->rps.hw_lock);
+       if (ret) {
+               DRM_ERROR("failed to inform pcode about cdclk change\n");
+               return;
+       }
+
+       val = I915_READ(LCPLL_CTL);
+       val |= LCPLL_CD_SOURCE_FCLK;
+       I915_WRITE(LCPLL_CTL, val);
+
+       if (wait_for_atomic_us(I915_READ(LCPLL_CTL) &
+                              LCPLL_CD_SOURCE_FCLK_DONE, 1))
+               DRM_ERROR("Switching to FCLK failed\n");
+
+       val = I915_READ(LCPLL_CTL);
+       val &= ~LCPLL_CLK_FREQ_MASK;
+
+       switch (cdclk) {
+       case 450000:
+               val |= LCPLL_CLK_FREQ_450;
+               data = 0;
+               break;
+       case 540000:
+               val |= LCPLL_CLK_FREQ_54O_BDW;
+               data = 1;
+               break;
+       case 337500:
+               val |= LCPLL_CLK_FREQ_337_5_BDW;
+               data = 2;
+               break;
+       case 675000:
+               val |= LCPLL_CLK_FREQ_675_BDW;
+               data = 3;
+               break;
+       default:
+               WARN(1, "invalid cdclk frequency\n");
+               return;
+       }
+
+       I915_WRITE(LCPLL_CTL, val);
+
+       val = I915_READ(LCPLL_CTL);
+       val &= ~LCPLL_CD_SOURCE_FCLK;
+       I915_WRITE(LCPLL_CTL, val);
+
+       if (wait_for_atomic_us((I915_READ(LCPLL_CTL) &
+                               LCPLL_CD_SOURCE_FCLK_DONE) == 0, 1))
+               DRM_ERROR("Switching back to LCPLL failed\n");
+
+       mutex_lock(&dev_priv->rps.hw_lock);
+       sandybridge_pcode_write(dev_priv, HSW_PCODE_DE_WRITE_FREQ_REQ, data);
+       mutex_unlock(&dev_priv->rps.hw_lock);
+
+       intel_update_cdclk(dev);
+
+       WARN(cdclk != dev_priv->cdclk_freq,
+            "cdclk requested %d kHz but got %d kHz\n",
+            cdclk, dev_priv->cdclk_freq);
+}
+
 static void haswell_modeset_global_pipes(struct drm_atomic_state *state,
                                         unsigned *prepare_pipes)
 {
@@ -9189,7 +9290,10 @@ static void haswell_modeset_global_resources(struct 
drm_atomic_state *state)
        int req_cdclk = haswell_calc_cdclk(dev_priv, max_pixel_rate);
 
        if (req_cdclk != dev_priv->cdclk_freq) {
-               haswell_set_cdclk(dev, req_cdclk);
+               if (IS_BROADWELL(dev))
+                       broadwell_set_cdclk(dev, req_cdclk);
+               else
+                       haswell_set_cdclk(dev, req_cdclk);
        }
 }
 
@@ -12349,7 +12453,7 @@ static int __intel_set_mode(struct drm_crtc *crtc,
         * mode set on this crtc.  For other crtcs we need to use the
         * adjusted_mode bits in the crtc directly.
         */
-       if (IS_VALLEYVIEW(dev) || IS_HASWELL(dev)) {
+       if (IS_VALLEYVIEW(dev) || IS_HASWELL(dev) || IS_BROADWELL(dev)) {
                if (IS_VALLEYVIEW(dev))
                        valleyview_modeset_global_pipes(state, &prepare_pipes);
                else
@@ -14387,9 +14491,9 @@ static void intel_init_display(struct drm_device *dev)
                dev_priv->display.fdi_link_train = ivb_manual_fdi_link_train;
        } else if (IS_HASWELL(dev) || IS_BROADWELL(dev)) {
                dev_priv->display.fdi_link_train = hsw_fdi_link_train;
-               if (IS_HASWELL(dev))
-                       dev_priv->display.modeset_global_resources =
-                               haswell_modeset_global_resources;
+               dev_priv->display.modeset_global_resources =
+                       haswell_modeset_global_resources;
+
        } else if (IS_VALLEYVIEW(dev)) {
                dev_priv->display.modeset_global_resources =
                        valleyview_modeset_global_resources;
-- 
1.9.1

_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/intel-gfx

Reply via email to