drm/i915/cnl: Allow 2 pixel per clock on Cannonlake.

This is heavily based on a initial patch provided by Ville
plus all changes provided later by Ander.

As Geminilake, Cannonlake also supports 2 pixels per clock.

Different from Geminilake we are not implementing the 99% Wa.
But we can revisit that decision later if we find out
any limitation on later CNL SKUs.

v2: Rebase on top of commit 'd305e0614601 ("drm/i915: Track
minimum acceptable cdclk instead of "minimum dotclock")'

v3: When fixing HDMI on CNL I noticed that I missed to convert
    back the doubled pixel rate to cdclk.

Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171003223142.26264-1-rodrigo.vivi@intel.com

diff --git a/drivers/gpu/drm/i915/intel_cdclk.c b/drivers/gpu/drm/i915/intel_cdclk.c
index 51cd23d..e8884c2 100644 (file)
--- a/drivers/gpu/drm/i915/intel_cdclk.c
+++ b/drivers/gpu/drm/i915/intel_cdclk.c
@@ -1866,12 +1866,7 @@ static int intel_pixel_rate_to_cdclk(struct drm_i915_private *dev_priv,
                                     int pixel_rate)
 {
        if (INTEL_GEN(dev_priv) >= 10)
-               /*
-                * FIXME: Switch to DIV_ROUND_UP(pixel_rate, 2)
-                * once DDI clock voltage requirements are
-                * handled correctly.
-                */
-               return pixel_rate;
+               return DIV_ROUND_UP(pixel_rate, 2);
        else if (IS_GEMINILAKE(dev_priv))
                /*
                 * FIXME: Avoid using a pixel clock that is more than 99% of the cdclk
@@ -2188,12 +2183,7 @@ static int intel_compute_max_dotclk(struct drm_i915_private *dev_priv)
        int max_cdclk_freq = dev_priv->max_cdclk_freq;
 
        if (INTEL_GEN(dev_priv) >= 10)
-               /*
-                * FIXME: Allow '2 * max_cdclk_freq'
-                * once DDI clock voltage requirements are
-                * handled correctly.
-                */
-               return max_cdclk_freq;
+               return 2 * max_cdclk_freq;
        else if (IS_GEMINILAKE(dev_priv))
                /*
                 * FIXME: Limiting to 99% as a temporary workaround. See

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 7d7952b..0e493a1 100644 (file)
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -12765,7 +12765,7 @@ skl_max_scale(struct intel_crtc *intel_crtc, struct intel_crtc_state *crtc_state
        crtc_clock = crtc_state->base.adjusted_mode.crtc_clock;
        max_dotclk = to_intel_atomic_state(crtc_state->base.state)->cdclk.logical.cdclk;
 
-       if (IS_GEMINILAKE(dev_priv))
+       if (IS_GEMINILAKE(dev_priv) || INTEL_GEN(dev_priv) >= 10)
                max_dotclk *= 2;
 
        if (WARN_ON_ONCE(!crtc_clock || max_dotclk < crtc_clock))

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 1ead517..742d545 100644 (file)
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -3932,6 +3932,7 @@ skl_pipe_downscale_amount(const struct intel_crtc_state *crtc_state)
 int skl_check_pipe_max_pixel_rate(struct intel_crtc *intel_crtc,
                                  struct intel_crtc_state *cstate)
 {
+       struct drm_i915_private *dev_priv = to_i915(intel_crtc->base.dev);
        struct drm_crtc_state *crtc_state = &cstate->base;
        struct drm_atomic_state *state = crtc_state->state;
        struct drm_plane *plane;
@@ -3974,7 +3975,7 @@ int skl_check_pipe_max_pixel_rate(struct intel_crtc *intel_crtc,
        crtc_clock = crtc_state->adjusted_mode.crtc_clock;
        dotclk = to_intel_atomic_state(state)->cdclk.logical.cdclk;
 
-       if (IS_GEMINILAKE(to_i915(intel_crtc->base.dev)))
+       if (IS_GEMINILAKE(dev_priv) || INTEL_GEN(dev_priv) >= 10)
                dotclk *= 2;
 
        pipe_max_pixel_rate = div_round_up_u32_fixed16(dotclk, pipe_downscale);