From: Matt Roper Date: Thu, 5 Sep 2019 18:13:37 +0000 (-0700) Subject: drm/i915/tgl: Use refclk/2 as bypass frequency X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=71cd86cfaa12645ca39e5bbeceb2039af74fba2e;p=linux.git drm/i915/tgl: Use refclk/2 as bypass frequency Unlike gen11, which always ran at 50MHz when the cdclk PLL was disabled, TGL runs at refclk/2. The 50MHz croclk/2 is only used by hardware during some power state transitions. Bspec: 49201 Cc: José Roberto de Souza Signed-off-by: Matt Roper Link: https://patchwork.freedesktop.org/patch/msgid/20190905181337.23727-1-matthew.d.roper@intel.com Reviewed-by: Ville Syrjälä --- diff --git a/drivers/gpu/drm/i915/display/intel_cdclk.c b/drivers/gpu/drm/i915/display/intel_cdclk.c index 76f11d465e91e..d3e56628af70b 100644 --- a/drivers/gpu/drm/i915/display/intel_cdclk.c +++ b/drivers/gpu/drm/i915/display/intel_cdclk.c @@ -1855,8 +1855,6 @@ static void icl_get_cdclk(struct drm_i915_private *dev_priv, u32 val; int div; - cdclk_state->bypass = 50000; - val = I915_READ(SKL_DSSM); switch (val & ICL_DSSM_CDCLK_PLL_REFCLK_MASK) { default: @@ -1873,6 +1871,11 @@ static void icl_get_cdclk(struct drm_i915_private *dev_priv, break; } + if (INTEL_GEN(dev_priv) >= 12) + cdclk_state->bypass = cdclk_state->ref / 2; + else + cdclk_state->bypass = 50000; + val = I915_READ(BXT_DE_PLL_ENABLE); if ((val & BXT_DE_PLL_PLL_ENABLE) == 0 || (val & BXT_DE_PLL_LOCK) == 0) {