Re: [PATCH v2] drm/i915: Make i9xx_crtc_clock_get() work for PCH DPLLs

Ville Syrjälä
2013-09-13T13:54:22Z

On Fri, Sep 13, 2013 at 04:47:53PM +0300, Jani Nikula wrote:
> On Fri, 13 Sep 2013, Ville Syrjälä <ville.syrjala@linux.intel.com> wrote:
> > On Fri, Sep 13, 2013 at 04:04:03PM +0300, Jani Nikula wrote:
> >> On Mon, 09 Sep 2013, ville.syrjala@linux.intel.com wrote:
> >> > From: Ville Syrjälä <ville.syrjala@linux.intel.com>
> >> >
> >> > Add the 120MHz refernce clock case for PCH DPLLs.
> >> >
> >> > Also determine the reference clock frequency more accurately by
> >> > checking for the PLLB_REF_INPUT_SPREADSPECTRUMIN refclk input
> >> > mode. The gen2 code already checked it, but it stil assumed a
> >> > fixed 66MHz refclk. Instead we need to consult the VBT for the
> >> > real value.
> >> >
> >> > v2: Fix refclk for SSC panel case
> >> >
> >> > Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> >> > ---
> >> > drivers/gpu/drm/i915/intel_display.c | 32 +++++++++++++++++++++-----------
> >> > 1 file changed, 21 insertions(+), 11 deletions(-)
> >> >
> >> > diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> >> > index 754de85..4f07292 100644
> >> > --- a/drivers/gpu/drm/i915/intel_display.c
> >> > +++ b/drivers/gpu/drm/i915/intel_display.c
> >> > @@ -7324,6 +7324,22 @@ void intel_release_load_detect_pipe(struct drm_connector *connector,
> >> > mutex_unlock(&crtc->mutex);
> >> > }
> >> >
> >> > +static int i9xx_pll_refclk(struct drm_device *dev,
> >> > + const struct intel_crtc_config *pipe_config)
> >> > +{
> >> > + struct drm_i915_private *dev_priv = dev->dev_private;
> >> > + u32 dpll = pipe_config->dpll_hw_state.dpll;
> >> > +
> >> > + if ((dpll & PLL_REF_INPUT_MASK) == PLLB_REF_INPUT_SPREADSPECTRUMIN)
> >>
> >> This seems wrong for at least gen3 and vlv. And it's a bit scary to go
> >> change gen2 but oh well...
> >
> > Why? i8xx_update_pll(), i9xx_update_pll() and ironlake_compute_dpll()
> > all have the same logic for setting that bit.
>
> My Super Reliable(tm) gen3 spec says reserved for that value
> there. *shrug*.

Looks like it's there only for pipe B and even then only for certain
platforms. But if we managed to program it w/ an invalid value I suspect
things fall apart in other ways.

>
> > For VLV I agree. But the clock readout there is totally busted anyway,
> > so I don't care at this point.
>
> Maybe Daniel can copy-paste something along those lines in the commit
> message. Or not. *shrug. :)
>
> Reviewed-by: Jani Nikula <jani.nikula@intel.com>
>
>
> >
> >>
> >> Jani.
> >>
> >> > + return dev_priv->vbt.lvds_ssc_freq * 1000;
> >> > + else if (HAS_PCH_SPLIT(dev))
> >> > + return 120000;
> >> > + else if (!IS_GEN2(dev))
> >> > + return 96000;
> >> > + else
> >> > + return 48000;
> >> > +}
> >> > +
> >> > /* Returns the clock of the currently programmed mode of the given pipe. */
> >> > static void i9xx_crtc_clock_get(struct intel_crtc *crtc,
> >> > struct intel_crtc_config *pipe_config)
> >> > @@ -7334,6 +7350,7 @@ static void i9xx_crtc_clock_get(struct intel_crtc *crtc,
> >> > u32 dpll = pipe_config->dpll_hw_state.dpll;
> >> > u32 fp;
> >> > intel_clock_t clock;
> >> > + int refclk = i9xx_pll_refclk(dev, pipe_config);
> >> >
> >> > if ((dpll & DISPLAY_RATE_SELECT_FPA1) == 0)
> >> > fp = pipe_config->dpll_hw_state.fp0;
> >> > @@ -7373,9 +7390,9 @@ static void i9xx_crtc_clock_get(struct intel_crtc *crtc,
> >> > }
> >> >
> >> > if (IS_PINEVIEW(dev))
> >> > - pineview_clock(96000, &clock);
> >> > + pineview_clock(refclk, &clock);
> >> > else
> >> > - i9xx_clock(96000, &clock);
> >> > + i9xx_clock(refclk, &clock);
> >> > } else {
> >> > bool is_lvds = (pipe == 1) && (I915_READ(LVDS) & LVDS_PORT_EN);
> >> >
> >> > @@ -7383,13 +7400,6 @@ static void i9xx_crtc_clock_get(struct intel_crtc *crtc,
> >> > clock.p1 = ffs((dpll & DPLL_FPA01_P1_POST_DIV_MASK_I830_LVDS) >>
> >> > DPLL_FPA01_P1_POST_DIV_SHIFT);
> >> > clock.p2 = 14;
> >> > -
> >> > - if ((dpll & PLL_REF_INPUT_MASK) ==
> >> > - PLLB_REF_INPUT_SPREADSPECTRUMIN) {
> >> > - /* XXX: might not be 66MHz */
> >> > - i9xx_clock(66000, &clock);
> >> > - } else
> >> > - i9xx_clock(48000, &clock);
> >> > } else {
> >> > if (dpll & PLL_P1_DIVIDE_BY_TWO)
> >> > clock.p1 = 2;
> >> > @@ -7401,9 +7411,9 @@ static void i9xx_crtc_clock_get(struct intel_crtc *crtc,
> >> > clock.p2 = 4;
> >> > else
> >> > clock.p2 = 2;
> >> > -
> >> > - i9xx_clock(48000, &clock);
> >> > }
> >> > +
> >> > + i9xx_clock(refclk, &clock);
> >> > }
> >> >
> >> > pipe_config->adjusted_mode.clock = clock.dot;
> >> > --
> >> > 1.8.1.5
> >> >
> >> > _______________________________________________
> >> > Intel-gfx mailing list
> >> > Intel-gfx@lists.freedesktop.org
> >> > http://lists.freedesktop.org/mailman/listinfo/intel-gfx
> >>
> >> --
> >> Jani Nikula, Intel Open Source Technology Center
> >
> > --
> > Ville Syrjälä
> > Intel OTC
>
> --
> Jani Nikula, Intel Open Source Technology Center

--
Ville Syrjälä
Intel OTC