[Intel-gfx] [PATCH 08/21] drm/i915: Keep track of preferred cdclk vco frequency on SKL
Imre Deak
imre.deak at intel.com
Thu May 19 14:25:43 UTC 2016
On pe, 2016-05-13 at 23:41 +0300, ville.syrjala at linux.intel.com wrote:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
>
> Now that skl_vco_freq tracks the actual DPLL0 vco frequency, we'll need
> something that keeps track of which vco frequency we want to use in case
> the current vco is 0. This would be important across supend/resume since
> we'll disable DPLL0 around those parts.
>
> We'll also update our idea of max cdclk/dotclock when the preferred
> vco changes. That could happen if out initial guess was wrong, and
> later eDP would force us to change it. One issue here could be that
> changing the max dotclock could cause our mode list to change during
> next time the displays get probed. But I don't see a good way to avoid
> that, except perhaps by allowing either vco frequency to be used as
> needed. But the docs suggest that such usage wasn't really inteded.
>
> Also need to make sure we don't update our max_cdclk value before we
> have a preferred vco value, which means moving that to happen after
> the cdclk sanitation.
>
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
Reviewed-by: Imre Deak <imre.deak at intel.com>
> ---
> drivers/gpu/drm/i915/i915_drv.h | 1 +
> drivers/gpu/drm/i915/intel_display.c | 48 +++++++++++++++++++++++++++++------
> drivers/gpu/drm/i915/intel_dpll_mgr.c | 5 ++++
> drivers/gpu/drm/i915/intel_drv.h | 1 +
> 4 files changed, 47 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index b319da970c8a..46a22732088e 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -1821,6 +1821,7 @@ struct drm_i915_private {
>
> unsigned int fsb_freq, mem_freq, is_ddr3;
> unsigned int skl_vco_freq;
> + unsigned int skl_preferred_vco_freq;
> unsigned int cdclk_freq, max_cdclk_freq, atomic_cdclk_freq;
> unsigned int max_dotclk_freq;
> unsigned int rawclk_freq;
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index cd2809179042..107a7799bdde 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -5265,21 +5265,34 @@ static int intel_compute_max_dotclk(struct drm_i915_private *dev_priv)
> return max_cdclk_freq*90/100;
> }
>
> +static int skl_calc_cdclk(int max_pixclk, int vco);
> +
> static void intel_update_max_cdclk(struct drm_device *dev)
> {
> struct drm_i915_private *dev_priv = dev->dev_private;
>
> if (IS_SKYLAKE(dev) || IS_KABYLAKE(dev)) {
> u32 limit = I915_READ(SKL_DFSM) & SKL_DFSM_CDCLK_LIMIT_MASK;
> + int max_cdclk, vco;
> +
> + vco = dev_priv->skl_preferred_vco_freq;
> + WARN_ON(vco != 8100 && vco != 8640);
>
> + /*
> + * Use the lower (vco 8640) cdclk values as a
> + * first guess. skl_calc_cdclk() will correct it
> + * if the preferred vco is 8100 instead.
> + */
> if (limit == SKL_DFSM_CDCLK_LIMIT_675)
> - dev_priv->max_cdclk_freq = 675000;
> + max_cdclk = 617140;
> else if (limit == SKL_DFSM_CDCLK_LIMIT_540)
> - dev_priv->max_cdclk_freq = 540000;
> + max_cdclk = 540000;
> else if (limit == SKL_DFSM_CDCLK_LIMIT_450)
> - dev_priv->max_cdclk_freq = 450000;
> + max_cdclk = 432000;
> else
> - dev_priv->max_cdclk_freq = 337500;
> + max_cdclk = 308570;
> +
> + dev_priv->max_cdclk_freq = skl_calc_cdclk(max_cdclk, vco);
> } else if (IS_BROXTON(dev)) {
> dev_priv->max_cdclk_freq = 624000;
> } else if (IS_BROADWELL(dev)) {
> @@ -5336,9 +5349,6 @@ static void intel_update_cdclk(struct drm_device *dev)
> */
> if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))
> I915_WRITE(GMBUSFREQ_VLV, DIV_ROUND_UP(dev_priv->cdclk_freq, 1000));
> -
> - if (dev_priv->max_cdclk_freq == 0)
> - intel_update_max_cdclk(dev);
> }
>
> /* convert from kHz to .1 fixpoint MHz with -1MHz offset */
> @@ -5587,12 +5597,24 @@ skl_dpll0_update(struct drm_i915_private *dev_priv)
> }
> }
>
> +void skl_set_preferred_cdclk_vco(struct drm_i915_private *dev_priv, int vco)
> +{
> + bool changed = dev_priv->skl_preferred_vco_freq != vco;
> +
> + dev_priv->skl_preferred_vco_freq = vco;
> +
> + if (changed)
> + intel_update_max_cdclk(dev_priv->dev);
> +}
> +
> static void
> skl_dpll0_enable(struct drm_i915_private *dev_priv, int vco)
> {
> int min_cdclk = skl_calc_cdclk(0, vco);
> u32 val;
>
> + WARN_ON(vco != 8100 && vco != 8640);
> +
> /* select the minimum CDCLK before enabling DPLL 0 */
> val = CDCLK_FREQ_337_308 | skl_cdclk_decimal(min_cdclk);
> I915_WRITE(CDCLK_CTL, val);
> @@ -5628,6 +5650,9 @@ skl_dpll0_enable(struct drm_i915_private *dev_priv, int vco)
> DRM_ERROR("DPLL0 not locked\n");
>
> dev_priv->skl_vco_freq = vco;
> +
> + /* We'll want to keep using the current vco from now on. */
> + skl_set_preferred_cdclk_vco(dev_priv, vco);
> }
>
> static void
> @@ -5744,7 +5769,9 @@ void skl_init_cdclk(struct drm_i915_private *dev_priv)
> int cdclk, vco;
>
> /* set CDCLK to the lowest frequency, Modeset follows */
> - vco = 8100;
> + vco = dev_priv->skl_preferred_vco_freq;
> + if (vco == 0)
> + vco = 8100;
> cdclk = skl_calc_cdclk(0, vco);
>
> skl_set_cdclk(dev_priv, cdclk, vco);
> @@ -13359,6 +13386,8 @@ static int intel_modeset_checks(struct drm_atomic_state *state)
> if (dev_priv->display.modeset_calc_cdclk) {
> if (!intel_state->cdclk_pll_vco)
> intel_state->cdclk_pll_vco = dev_priv->skl_vco_freq;
> + if (!intel_state->cdclk_pll_vco)
> + intel_state->cdclk_pll_vco = dev_priv->skl_preferred_vco_freq;
>
> ret = dev_priv->display.modeset_calc_cdclk(state);
> if (ret < 0)
> @@ -15525,6 +15554,9 @@ void intel_modeset_init(struct drm_device *dev)
>
> intel_shared_dpll_init(dev);
>
> + if (dev_priv->max_cdclk_freq == 0)
> + intel_update_max_cdclk(dev);
> +
> /* Just disable it once at startup */
> i915_disable_vga(dev);
> intel_setup_outputs(dev);
> diff --git a/drivers/gpu/drm/i915/intel_dpll_mgr.c b/drivers/gpu/drm/i915/intel_dpll_mgr.c
> index 5391ab66b64d..34ec149fde85 100644
> --- a/drivers/gpu/drm/i915/intel_dpll_mgr.c
> +++ b/drivers/gpu/drm/i915/intel_dpll_mgr.c
> @@ -1635,6 +1635,11 @@ static void intel_ddi_pll_init(struct drm_device *dev)
> if (IS_SKYLAKE(dev) || IS_KABYLAKE(dev)) {
> if (skl_sanitize_cdclk(dev_priv))
> DRM_DEBUG_KMS("Sanitized cdclk programmed by pre-os\n");
> +
> + /* We'll want to keep using the current vco from now on */
> + if (dev_priv->skl_vco_freq != 0)
> + skl_set_preferred_cdclk_vco(dev_priv,
> + dev_priv->skl_vco_freq);
> } else if (!IS_BROXTON(dev_priv)) {
> /*
> * The LCPLL register should be turned on by the BIOS. For now
> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> index c7cb9829547e..8f48a32e991b 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -1145,6 +1145,7 @@ void i915_audio_component_init(struct drm_i915_private *dev_priv);
> void i915_audio_component_cleanup(struct drm_i915_private *dev_priv);
>
> /* intel_display.c */
> +void skl_set_preferred_cdclk_vco(struct drm_i915_private *dev_priv, int vco);
> void intel_update_rawclk(struct drm_i915_private *dev_priv);
> int vlv_get_cck_clock(struct drm_i915_private *dev_priv,
> const char *name, u32 reg, int ref_freq);
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