On Tue, 2016-11-01 at 21:35 +0200, Jani Nikula wrote: > On Tue, 01 Nov 2016, Dhinakaran Pandiyan <dhinakaran.pandiyan@xxxxxxxxx> wrote: > > 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. > > I'm too tired to read bspec now, but is gen9 really the answer, or just > Skylake? > > Gen9, applies to BXT and KBL as well. -DK > > > > 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> > > --- > > 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..c0ae147 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_device *dev = crtc_state->base.crtc->dev; > > Nitpick, I guess I'd make that > > struct drm_i915_private *dev_priv = to_i915(crtc_state->base.crtc->dev); > > but no big deal. > > > + > > /* pixel rate mustn't exceed 95% of cdclk with IPS on BDW */ > > - if (crtc_state->ips_enabled) > > + if (IS_BROADWELL(to_i915(dev)) && 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); > _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
