On Wed, May 02, 2018 at 10:12:51PM +0300, Ville Syrjälä wrote:
> On Wed, May 02, 2018 at 10:52:55AM -0700, Rodrigo Vivi wrote:
> > On intel_dp_compute_config() we were calculating the needed vco
> > for eDP on gen9 and we stashing it in
> > intel_atomic_state.cdclk.logical.vco
> >
> > However few moments later on intel_modeset_checks() we fully
> > replace entire intel_atomic_state.cdclk.logical with
> > dev_priv->cdclk.logical fully overwriting the logical desired
> > vco for eDP on gen9.
> >
> > So, with wrong VCO value we end up with wrong desired cdclk, but
> > also it will raise a lot of WARNs: On gen9, when we read
> > CDCLK_CTL to verify if we configured properly the desired
> > frequency the CD Frequency Select bits [27:26] == 10b can mean
> > 337.5 or 308.57 MHz depending on the VCO. So if we have wrong
> > VCO value stashed we will believe the frequency selection didn't
> > stick and start to raise WARNs of cdclk mismatch.
> >
> > [ 42.857519] [drm:intel_dump_cdclk_state [i915]] Changing CDCLK to 308571
> > kHz, VCO 8640000 kHz, ref 24000 kHz, bypass 24000 kHz, voltage level 0
> > [ 42.897269] cdclk state doesn't match!
> > [ 42.901052] WARNING: CPU: 5 PID: 1116 at
> > drivers/gpu/drm/i915/intel_cdclk.c:2084 intel_set_cdclk+0x5d/0x110 [i915]
> > [ 42.938004] RIP: 0010:intel_set_cdclk+0x5d/0x110 [i915]
> > [ 43.155253] WARNING: CPU: 5 PID: 1116 at
> > drivers/gpu/drm/i915/intel_cdclk.c:2084 intel_set_cdclk+0x5d/0x110 [i915]
> > [ 43.170277] [drm:intel_dump_cdclk_state [i915]] [hw state] 337500 kHz,
> > VCO 8100000 kHz, ref 24000 kHz, bypass 24000 kHz, voltage level 0
> > [ 43.182566] [drm:intel_dump_cdclk_state [i915]] [sw state] 308571 kHz,
> > VCO 8640000 kHz, ref 24000 kHz, bypass 24000 kHz, voltage level 0
> >
> > v2: Move the entire eDP's vco logical adjustment to inside
> > the skl_modeset_calc_cdclk as suggested by Ville.
> >
> > Cc: Ville Syrjälä <[email protected]>
> > Signed-off-by: Rodrigo Vivi <[email protected]>
> > ---
> > drivers/gpu/drm/i915/intel_cdclk.c | 41
> > ++++++++++++++++++++++++++++++++++----
> > drivers/gpu/drm/i915/intel_dp.c | 20 -------------------
> > 2 files changed, 37 insertions(+), 24 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/intel_cdclk.c
> > b/drivers/gpu/drm/i915/intel_cdclk.c
> > index 32d24c69da3c..704ddb4d3ca7 100644
> > --- a/drivers/gpu/drm/i915/intel_cdclk.c
> > +++ b/drivers/gpu/drm/i915/intel_cdclk.c
> > @@ -2302,9 +2302,44 @@ static int bdw_modeset_calc_cdclk(struct
> > drm_atomic_state *state)
> > return 0;
> > }
> >
> > +static int skl_dpll0_vco(struct intel_atomic_state *intel_state)
> > +{
> > + struct drm_i915_private *dev_priv = to_i915(intel_state->base.dev);
> > + struct intel_crtc *crtc;
> > + struct intel_crtc_state *crtc_state;
> > + int vco, i;
> > +
> > + vco = intel_state->cdclk.logical.vco;
> > + if (!vco)
> > + vco = dev_priv->skl_preferred_vco_freq;
> > +
> > + for_each_new_intel_crtc_in_state(intel_state, crtc, crtc_state, i) {
> > + if (!crtc_state->base.enable)
> > + continue;
> > +
> > + if (!intel_crtc_has_type(crtc_state, INTEL_OUTPUT_EDP))
> > + continue;
> > +
> > + /*
> > + * DPLL0 VCO may need to be adjusted to get the correct
> > + * clock for eDP. This will affect cdclk as well.
> > + */
> > + switch (crtc_state->port_clock / 2) {
> > + case 108000:
> > + case 216000:
> > + vco = 8640000;
> > + break;
> > + default:
> > + vco = 8100000;
> > + break;
> > + }
> > + }
> > +
> > + return vco;
> > +}
>
> Yep. I think this should do the right thing. For the times when the pipe
> driving eDP isn't part of the atomic state we wil simply preserve the
> current vco setting. That means other pipes can't actually make a mess
> of the DPLL0 VCO while eDP depends on it.
>
> Reviewed-by: Ville Syrjälä <[email protected]>
Thanks for the suggestions.
So, on setting the examples of what *not* to do: I forgot to include
Fixes: and cc stable.
Luckily I remembered before pushing. So,
Fixes: bb0f4aab0e76 ("drm/i915: Track full cdclk state for the logical and
actual cdclk frequencies")
Cc: <[email protected]> # v4.12+
seems right for you?
>
> > +
> > static int skl_modeset_calc_cdclk(struct drm_atomic_state *state)
> > {
> > - struct drm_i915_private *dev_priv = to_i915(state->dev);
> > struct intel_atomic_state *intel_state = to_intel_atomic_state(state);
> > int min_cdclk, cdclk, vco;
> >
> > @@ -2312,9 +2347,7 @@ static int skl_modeset_calc_cdclk(struct
> > drm_atomic_state *state)
> > if (min_cdclk < 0)
> > return min_cdclk;
> >
> > - vco = intel_state->cdclk.logical.vco;
> > - if (!vco)
> > - vco = dev_priv->skl_preferred_vco_freq;
> > + vco = skl_dpll0_vco(intel_state);
> >
> > /*
> > * FIXME should also account for plane ratio
> > diff --git a/drivers/gpu/drm/i915/intel_dp.c
> > b/drivers/gpu/drm/i915/intel_dp.c
> > index 83da50b13d81..dde92e4af5d3 100644
> > --- a/drivers/gpu/drm/i915/intel_dp.c
> > +++ b/drivers/gpu/drm/i915/intel_dp.c
> > @@ -1929,26 +1929,6 @@ intel_dp_compute_config(struct intel_encoder
> > *encoder,
> > reduce_m_n);
> > }
> >
> > - /*
> > - * DPLL0 VCO may need to be adjusted to get the correct
> > - * clock for eDP. This will affect cdclk as well.
> > - */
> > - if (intel_dp_is_edp(intel_dp) && IS_GEN9_BC(dev_priv)) {
> > - int vco;
> > -
> > - switch (pipe_config->port_clock / 2) {
> > - case 108000:
> > - case 216000:
> > - vco = 8640000;
> > - break;
> > - default:
> > - vco = 8100000;
> > - break;
> > - }
> > -
> > -
> > to_intel_atomic_state(pipe_config->base.state)->cdclk.logical.vco = vco;
> > - }
> > -
> > if (!HAS_DDI(dev_priv))
> > intel_dp_set_clock(encoder, pipe_config);
> >
> > --
> > 2.13.6
>
> --
> Ville Syrjälä
> Intel
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