diff --git a/drivers/gpu/drm/i915/intel_cdclk.c b/drivers/gpu/drm/i915/intel_cdclk.c index dd3ad52b7dfeac5e7d6f8eb59ee18b372f20a77f..763010f8ad8968e6f226e0f94a704069b4418b94 100644 --- a/drivers/gpu/drm/i915/intel_cdclk.c +++ b/drivers/gpu/drm/i915/intel_cdclk.c @@ -1071,9 +1071,15 @@ static int bxt_calc_cdclk(int max_pixclk) static int glk_calc_cdclk(int max_pixclk) { - if (max_pixclk > 2 * 158400) + /* + * FIXME: Avoid using a pixel clock that is more than 99% of the cdclk + * as a temporary workaround. Use a higher cdclk instead. (Note that + * intel_compute_max_dotclk() limits the max pixel clock to 99% of max + * cdclk.) + */ + if (max_pixclk > DIV_ROUND_UP(2 * 158400 * 99, 100)) return 316800; - else if (max_pixclk > 2 * 79200) + else if (max_pixclk > DIV_ROUND_UP(2 * 79200 * 99, 100)) return 158400; else return 79200; @@ -1664,7 +1670,11 @@ static int intel_compute_max_dotclk(struct drm_i915_private *dev_priv) int max_cdclk_freq = dev_priv->max_cdclk_freq; if (IS_GEMINILAKE(dev_priv)) - return 2 * max_cdclk_freq; + /* + * FIXME: Limiting to 99% as a temporary workaround. See + * glk_calc_cdclk() for details. + */ + return 2 * max_cdclk_freq * 99 / 100; else if (INTEL_INFO(dev_priv)->gen >= 9 || IS_HASWELL(dev_priv) || IS_BROADWELL(dev_priv)) return max_cdclk_freq;