On Thu, Oct 08, 2015 at 05:43:41PM +0530, Kumar, Shobhit wrote:
> On 10/08/2015 04:59 PM, Imre Deak wrote:
> > On to, 2015-10-08 at 09:58 +0530, Shobhit Kumar wrote:
> >> Reuse what is programmed by pre-os, but in case there is no pre-os
> >> initialization, init the cdclk with the max value by default untill
> >> dynamic cdclk support comes.
> >>
> >> v2: Check if BIOS programmed correctly rather than always calling init
> >> - Do validation of programmed cdctl and what it is expected
> >> - Only do slk_init_cdclk if validation failed else reuse BIOS
> >> programmed value
> >>
> >> Cc: Imre Deak <imre.d...@intel.com>
> >> Cc: Ville Syrjälä <ville.syrj...@linux.intel.com>
> >> Signed-off-by: Shobhit Kumar <shobhit.ku...@intel.com>
> >> ---
> >> drivers/gpu/drm/i915/intel_ddi.c | 18 ++++++++++++-----
> >> drivers/gpu/drm/i915/intel_display.c | 39
> >> +++++++++++++++++++++++++++---------
> >> 2 files changed, 42 insertions(+), 15 deletions(-)
> >>
> >> diff --git a/drivers/gpu/drm/i915/intel_ddi.c
> >> b/drivers/gpu/drm/i915/intel_ddi.c
> >> index 2d3cc82..3ec5618 100644
> >> --- a/drivers/gpu/drm/i915/intel_ddi.c
> >> +++ b/drivers/gpu/drm/i915/intel_ddi.c
> >> @@ -2946,11 +2946,19 @@ void intel_ddi_pll_init(struct drm_device *dev)
> >> int cdclk_freq;
> >>
> >> cdclk_freq = dev_priv->display.get_display_clock_speed(dev);
> >> - dev_priv->skl_boot_cdclk = cdclk_freq;
> >> - if (!(I915_READ(LCPLL1_CTL) & LCPLL_PLL_ENABLE))
> >> - DRM_ERROR("LCPLL1 is disabled\n");
> >> - else
> >> - intel_display_power_get(dev_priv, POWER_DOMAIN_PLLS);
> >> +
> >> + /* Invalid CDCLK from BIOS ? */
> >> + if (cdclk_freq < 0) {
> >> + /* program to maximum cdclk till we have dynamic cdclk
> >> support */
> >> + dev_priv->skl_boot_cdclk = 675000;
> >> + skl_init_cdclk(dev_priv);
> >
> > This would still try to reprogram CDCLK if BIOS enabled an output with
> > an incorrect CDCLK decimal part. Isn't this the exact scenario you're
> > seeing? As said before reprogramming CDCLK in that case would require
> > disabling the outputs first.
>
> I went with the hypothesis that if VBIOS/GOP was loaded it would have to
> correct the cdclock, with wrong decimal value display cannot be enabled.
> For example AUX will fail on SKL. So for correct display output enabled
> cdclock has to be correctly programmed. If it is wrong display was not
> enabled at all.
>
> The scenario which I am seeing is VBIOS/GOP is not loaded at all, and
> the pre-os is not leaving cdclock in correct state.
But it still enabled DPLL0? Why does it do that if it doesn't set up
cdclk?
>
> >
> > We would also need to call skl_init_cdclk if the BIOS hasn't enabled the
> > PLL for some reason. But I guess that could be a separate change.
> >
> >> + } else {
> >> + dev_priv->skl_boot_cdclk = cdclk_freq;
> >> + if (!(I915_READ(LCPLL1_CTL) & LCPLL_PLL_ENABLE))
> >> + DRM_ERROR("LCPLL1 is disabled\n");
> >> + else
> >> + intel_display_power_get(dev_priv,
> >> POWER_DOMAIN_PLLS);
> >> + }
> >> } else if (IS_BROXTON(dev)) {
> >> broxton_init_cdclk(dev);
> >> broxton_ddi_phy_init(dev);
> >> diff --git a/drivers/gpu/drm/i915/intel_display.c
> >> b/drivers/gpu/drm/i915/intel_display.c
> >> index bbeb6d3..f734410 100644
> >> --- a/drivers/gpu/drm/i915/intel_display.c
> >> +++ b/drivers/gpu/drm/i915/intel_display.c
> >> @@ -6634,12 +6634,15 @@ static int skylake_get_display_clock_speed(struct
> >> drm_device *dev)
> >> uint32_t lcpll1 = I915_READ(LCPLL1_CTL);
> >> uint32_t cdctl = I915_READ(CDCLK_CTL);
> >> uint32_t linkrate;
> >> + int freq;
> >>
> >> if (!(lcpll1 & LCPLL_PLL_ENABLE))
> >> return 24000; /* 24MHz is the cd freq with NSSC ref */
> >>
> >> - if ((cdctl & CDCLK_FREQ_SEL_MASK) == CDCLK_FREQ_540)
> >> - return 540000;
> >> + if ((cdctl & CDCLK_FREQ_SEL_MASK) == CDCLK_FREQ_540) {
> >> + freq = 540000;
> >> + goto verify;
> >> + }
> >>
> >> linkrate = (I915_READ(DPLL_CTRL1) &
> >> DPLL_CTRL1_LINK_RATE_MASK(SKL_DPLL0)) >> 1;
> >> @@ -6649,30 +6652,46 @@ static int skylake_get_display_clock_speed(struct
> >> drm_device *dev)
> >> /* vco 8640 */
> >> switch (cdctl & CDCLK_FREQ_SEL_MASK) {
> >> case CDCLK_FREQ_450_432:
> >> - return 432000;
> >> + freq = 432000;
> >> + break;
> >> case CDCLK_FREQ_337_308:
> >> - return 308570;
> >> + freq = 308570;
> >> + break;
> >> case CDCLK_FREQ_675_617:
> >> - return 617140;
> >> + freq = 617140;
> >> + break;
> >> default:
> >> WARN(1, "Unknown cd freq selection\n");
> >> + return -EINVAL;
> >> }
> >> } else {
> >> /* vco 8100 */
> >> switch (cdctl & CDCLK_FREQ_SEL_MASK) {
> >> case CDCLK_FREQ_450_432:
> >> - return 450000;
> >> + freq = 450000;
> >> + break;
> >> case CDCLK_FREQ_337_308:
> >> - return 337500;
> >> + freq = 337500;
> >> + break;
> >> case CDCLK_FREQ_675_617:
> >> - return 675000;
> >> + freq = 675000;
> >> + break;
> >> default:
> >> WARN(1, "Unknown cd freq selection\n");
> >> + return -EINVAL;
> >> }
> >> }
> >>
> >> - /* error case, do as if DPLL0 isn't enabled */
> >> - return 24000;
> >> +verify:
> >> + /*
> >> + * Noticed in some instances that the freq selection is correct but
> >> + * decimal part is programmed wrong from BIOS where pre-os does not
> >> + * enable display. Verify the same as well.
> >> + */
> >> + if (cdctl == ((cdctl & CDCLK_FREQ_SEL_MASK) | skl_cdclk_decimal(freq)))
> >> + return freq;
> >> + else
> >> + return -EINVAL;
> >> }
> >>
> >> static int broxton_get_display_clock_speed(struct drm_device *dev)
> >
> >
> > _______________________________________________
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> > Intel-gfx@lists.freedesktop.org
> > http://lists.freedesktop.org/mailman/listinfo/intel-gfx
> >
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--
Ville Syrjälä
Intel OTC
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