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

[Rodrigo Vivi]

On Tue, Sep 26, 2017 at 12:43 PM, Rodrigo Vivi <rodrigo.vivi at intel.com> wrote:
> 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 at intel.com>
> Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>
> Cc: Jani Nikula <jani.nikula at intel.com>
> Signed-off-by: Rodrigo Vivi <rodrigo.vivi at 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.
> -                */

this actually depends on https://patchwork.freedesktop.org/series/30922/

So I will probably resend this after that patch is merged, but I'd
appreciate early reviews.

> -               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
>
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-- 
Rodrigo Vivi
Blog: http://blog.vivi.eng.br