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

Rodrigo Vivi
2017-09-26T19:43:26Z

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")'

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>
---
drivers/gpu/drm/i915/intel_cdclk.c | 7 +------
drivers/gpu/drm/i915/intel_display.c | 2 +-
drivers/gpu/drm/i915/intel_pm.c | 3 ++-
3 files changed, 4 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_cdclk.c b/drivers/gpu/drm/i915/intel_cdclk.c
index d6befabd6ed5..eabaf57b83ef 100644
--- a/drivers/gpu/drm/i915/intel_cdclk.c
+++ b/drivers/gpu/drm/i915/intel_cdclk.c
@@ -1995,12 +1995,7 @@ 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 026fa5460fe5..487b43ba3139 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -12801,7 +12801,7 @@ 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 c66af09e27a7..52c4c194aa51 100644
--- 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);
--
2.13.5