[Intel-gfx] [PATCH 32/67] drm/i915/cnl: DDI - PLL mapping
Ville Syrjälä
ville.syrjala at linux.intel.com
Thu May 4 12:44:04 UTC 2017
On Thu, May 04, 2017 at 03:35:51PM +0300, Ander Conselvan De Oliveira wrote:
> On Fri, 2017-04-07 at 18:12 -0300, Paulo Zanoni wrote:
> > Em Qui, 2017-04-06 às 12:15 -0700, Rodrigo Vivi escreveu:
> > > One of the steps for PLL (un)initialization is to (un)map
> > > the correspondent DDI that is actually using that PLL.
> > >
> > > So, let's do this step following the places already stablished
> > > and used so far, although spec put this as part of PLL
> > > initialization sequences.
> > >
> > > v2: Use proper prefix on bits names as suggested by Ander.
> > > v3: Add missed "~". Without that the logic was inverted
> > > so we were disabling interrupts.
> > > Credits-to: Clinton
> > > Credits-to: Art
> > > v4: Spec is getting updated to do DDI -> PLL mapping
> > > and clock on in 2 separated reg writes. (Paulo)
> > > Also update bits definitions to use space
> > > (1 << 1) instead of (1<<1). (Paulo)
> > >
> > > Cc: Paulo Zanoni <paulo.r.zanoni at intel.com>
> > > Cc: Art Runyan <arthur.j.runyan at intel.com>
> > > Cc: Clint Taylor <clinton.a.taylor at intel.com>
> > > Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > > Cc: Kahola, Mika <mika.kahola at intel.com>
> > > Cc: Ander Conselvan De Oliveira <ander.conselvan.de.oliveira at intel.co
> > > m>
> > > Signed-off-by: Rodrigo Vivi <rodrigo.vivi at intel.com>
> > > Reviewed-by: Kahola, Mika <mika.kahola at intel.com>
> > > Signed-off-by: Rodrigo Vivi <rodrigo.vivi at intel.com>
> > > ---
> > > drivers/gpu/drm/i915/i915_reg.h | 9 +++++++++
> > > drivers/gpu/drm/i915/intel_ddi.c | 23 ++++++++++++++++++++---
> > > 2 files changed, 29 insertions(+), 3 deletions(-)
> > >
> > > diff --git a/drivers/gpu/drm/i915/i915_reg.h
> > > b/drivers/gpu/drm/i915/i915_reg.h
> > > index 3cfc65f..dcb8e21 100644
> > > --- a/drivers/gpu/drm/i915/i915_reg.h
> > > +++ b/drivers/gpu/drm/i915/i915_reg.h
> > > @@ -8150,6 +8150,15 @@ enum {
> > > #define DPLL_CFGCR1(id) _MMIO_PIPE((id) - SKL_DPLL1,
> > > _DPLL1_CFGCR1, _DPLL2_CFGCR1)
> > > #define DPLL_CFGCR2(id) _MMIO_PIPE((id) - SKL_DPLL1,
> > > _DPLL1_CFGCR2, _DPLL2_CFGCR2)
> > >
> > > +/*
> > > + * CNL Clocks
> > > + */
> > > +#define DPCLKA_CFGCR0 _MMIO(0x6C200)
> > > +#define DPCLKA_CFGCR0_DDI_CLK_OFF(port) (1 << ((port)+10))
> > > +#define DPCLKA_CFGCR0_DDI_CLK_SEL_MASK(port) (3 <<
> > > ((port)*2))
> > > +#define DPCLKA_CFGCR0_DDI_CLK_SEL_SHIFT(port) ((port)*2)
> > > +#define DPCLKA_CFGCR0_DDI_CLK_SEL(pll, port) ((pll) <<
> > > ((port)*2))
> > > +
> > > /* BXT display engine PLL */
> > > #define BXT_DE_PLL_CTL _MMIO(0x6d000)
> > > #define BXT_DE_PLL_RATIO(x) (x) /*
> > > {60,65,100} * 19.2MHz */
> > > diff --git a/drivers/gpu/drm/i915/intel_ddi.c
> > > b/drivers/gpu/drm/i915/intel_ddi.c
> > > index 0914ad9..2a901bf 100644
> > > --- a/drivers/gpu/drm/i915/intel_ddi.c
> > > +++ b/drivers/gpu/drm/i915/intel_ddi.c
> > > @@ -1621,13 +1621,27 @@ static void intel_ddi_clk_select(struct
> > > intel_encoder *encoder,
> > > {
> > > struct drm_i915_private *dev_priv = to_i915(encoder-
> > > > base.dev);
> > >
> > > enum port port = intel_ddi_get_encoder_port(encoder);
> > > + uint32_t val;
> > >
> > > if (WARN_ON(!pll))
> > > return;
> > >
> > > - if (IS_GEN9_BC(dev_priv)) {
> > > - uint32_t val;
> > > + if (IS_CANNONLAKE(dev_priv)) {
> > > + /* Configure DPCLKA_CFGCR0 to map the DPLL to the
> > > DDI. */
> > > + val = I915_READ(DPCLKA_CFGCR0);
> > > + val |= DPCLKA_CFGCR0_DDI_CLK_SEL(pll->id, port);
> > > + I915_WRITE(DPCLKA_CFGCR0, val);
> >
> > A question to the Atomic Lords: don't we need some sort of locking
> > around this register since it's used by all ports/clocks? I suppose
> > dev_priv->dpll_lock would do...
> >
> > Maybe the same would apply for gen9_bc.
>
> If there are modesets happening in parallel for different crtcs, then some
> locking is needed. dpll_lock seems like the right call, that's what's used to
> avoid the same problem with the enable/disable hooks.
If something is allowing modesets to commit in parallel then probably
the whole world is on fire. Historically connection_mutex has been there
to protect us, but not sure how that goes with nonblocking commits. I
do hope there's still something there to prevents this...
>
> Btw, I think this patch shows why something like [1] might be a good idea.
>
> [1] https://patchwork.freedesktop.org/patch/113598/
> >
> > >
> > > + /*
> > > + * Configure DPCLKA_CFGCR0 to turn on the clock for
> > > the DDI.
> > > + * This step and the step before must be done with
> > > separate
> > > + * register writes.
> > > + */
> > > + val = I915_READ(DPCLKA_CFGCR0);
> > > + val &= ~(DPCLKA_CFGCR0_DDI_CLK_OFF(port) |
> > > + DPCLKA_CFGCR0_DDI_CLK_SEL_MASK(port));
> > > + I915_WRITE(DPCLKA_CFGCR0, val);
> > > + } else if (IS_GEN9_BC(dev_priv)) {
> > > /* DDI -> PLL mapping */
> > > val = I915_READ(DPLL_CTRL2);
> > >
> > > @@ -1763,7 +1777,10 @@ static void intel_ddi_post_disable(struct
> > > intel_encoder *intel_encoder,
> > > if (dig_port)
> > > intel_display_power_put(dev_priv, dig_port-
> > > > ddi_io_power_domain);
> > >
> > >
> > > - if (IS_GEN9_BC(dev_priv))
> > > + if (IS_CANNONLAKE(dev_priv))
> > > + I915_WRITE(DPCLKA_CFGCR0, I915_READ(DPCLKA_CFGCR0) |
> > > + DPCLKA_CFGCR0_DDI_CLK_OFF(port));
> > > + else if (IS_GEN9_BC(dev_priv))
> > > I915_WRITE(DPLL_CTRL2, (I915_READ(DPLL_CTRL2) |
> > > DPLL_CTRL2_DDI_CLK_OFF(port)
> > > ));
> > > else if (INTEL_GEN(dev_priv) < 9)
> >
> > _______________________________________________
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> > Intel-gfx at lists.freedesktop.org
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--
Ville Syrjälä
Intel OTC
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