According to BSpec, cdclk for BDW has to be not less than 432 MHz with DP audio enabled, port width x4, and link rate HBR2 (5.4 GHz). With cdclk less than 432 MHz, enabling audio leads to pipe FIFO underruns and displays cycling on/off. Let's apply this work around to GEN9 platforms too, as it fixes the same issue. v2: Move drm_device to drm_i915_private conversion Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=97907 Cc: stable@xxxxxxxxxxxxxxx Cc: Libin Yang <libin.yang@xxxxxxxxxxxxxxx> Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@xxxxxxxxx> Reviewed-by: Jani Nikula <jani.nikula@xxxxxxxxx> --- drivers/gpu/drm/i915/intel_display.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 37483ee..0d95a2e 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -10264,8 +10264,10 @@ static void bxt_modeset_commit_cdclk(struct drm_atomic_state *old_state) static int bdw_adjust_min_pipe_pixel_rate(struct intel_crtc_state *crtc_state, int pixel_rate) { + struct drm_i915_private *dev_priv = to_i915(crtc_state->base.crtc->dev); + /* pixel rate mustn't exceed 95% of cdclk with IPS on BDW */ - if (crtc_state->ips_enabled) + if (IS_BROADWELL(dev_priv) && crtc_state->ips_enabled) pixel_rate = DIV_ROUND_UP(pixel_rate * 100, 95); /* BSpec says "Do not use DisplayPort with CDCLK less than @@ -10307,7 +10309,7 @@ static int ilk_max_pixel_rate(struct drm_atomic_state *state) pixel_rate = ilk_pipe_pixel_rate(crtc_state); - if (IS_BROADWELL(dev_priv)) + if (IS_BROADWELL(dev_priv) || IS_GEN9(dev_priv)) pixel_rate = bdw_adjust_min_pipe_pixel_rate(crtc_state, pixel_rate); -- 2.7.4 _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
