On Fri, 2017-12-22 at 21:58 +0200, Ville Syrjälä wrote:
> On Mon, Dec 04, 2017 at 03:22:10PM -0800, Lucas De Marchi wrote:
> > Display WA #1183 was recently added to workaround
> > "Failures when enabling DPLL0 with eDP link rate 2.16
> > or 4.32 GHz and CD clock frequency 308.57 or 617.14 MHz
> > (CDCLK_CTL CD Frequency Select 10b or 11b) used in this
> > enabling or in previous enabling."
> >
> > This workaround was designed to minimize the impact only
> > to save the bad case with that link rates. But HW engineers
> > indicated that it should be safe to apply broadly, although
> > they were expecting the DPLL0 link rate to be unchanged on
> > runtime.
> >
> > We need to cover 2 cases: when we are in fact enabling DPLL0
> > and when we are just changing the frequency with small
> > differences.
> >
> > This is based on previous patch by Rodrigo Vivi with suggestions
> > from Ville Syrjälä.
> >
> > Cc: Arthur J Runyan <arthur.j.runyan@xxxxxxxxx>
> > Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
> > Cc: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
> > Cc: stable@xxxxxxxxxxxxxxx
> > Signed-off-by: Lucas De Marchi <lucas.demarchi@xxxxxxxxx>
>
> Hmm. This is v4, but it was posted after v5?
>
> You didn't include a changelog in the commit message so I have no idea
> what is the difference between these versions. They appear similar on a
> first glance.
Sorry about the confusion. What happened is that first I was using the version
number accounting for the initial version Rodrigo sent. However, later I ended
up using the version from patchwork, which don't take Rodrigo's initial
version into account, even if the subject is the same.
The diff is only the CC to stable with additional commits to cherry-pick on
stable versions as requested by Jani.
Lucas De Marchi
> The changes here *look* correct to me, so
> Reviewed-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
>
> But I'm not going to push this right now because I'm too confused about
> the version of the patch. I'll be out for a few weeks so if the
> confusion is lifted during that time and you want this in please poke
> at someone else to push it.
>
> > ---
> > drivers/gpu/drm/i915/i915_reg.h | 2 ++
> > drivers/gpu/drm/i915/intel_cdclk.c | 35 ++++++++++++++++++++++++--
> > -------
> > drivers/gpu/drm/i915/intel_runtime_pm.c | 10 ++++++++++
> > 3 files changed, 38 insertions(+), 9 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/i915_reg.h
> > b/drivers/gpu/drm/i915/i915_reg.h
> > index 09bf043c1c2e..73335e709ed6 100644
> > --- a/drivers/gpu/drm/i915/i915_reg.h
> > +++ b/drivers/gpu/drm/i915/i915_reg.h
> > @@ -7021,6 +7021,7 @@ enum {
> > #define RESET_PCH_HANDSHAKE_ENABLE (1<<4)
> >
> > #define GEN8_CHICKEN_DCPR_1 _MMIO(0x46430)
> > +#define SKL_SELECT_ALTERNATE_DC_EXIT (1<<30)
> > #define MASK_WAKEMEM (1<<13)
> >
> > #define SKL_DFSM _MMIO(0x51000)
> > @@ -8575,6 +8576,7 @@ enum skl_power_gate {
> > #define BXT_CDCLK_CD2X_DIV_SEL_2 (2<<22)
> > #define BXT_CDCLK_CD2X_DIV_SEL_4 (3<<22)
> > #define BXT_CDCLK_CD2X_PIPE(pipe) ((pipe)<<20)
> > +#define CDCLK_DIVMUX_CD_OVERRIDE (1<<19)
> > #define BXT_CDCLK_CD2X_PIPE_NONE BXT_CDCLK_CD2X_PIPE(3)
> > #define BXT_CDCLK_SSA_PRECHARGE_ENABLE (1<<16)
> > #define CDCLK_FREQ_DECIMAL_MASK (0x7ff)
> > diff --git a/drivers/gpu/drm/i915/intel_cdclk.c
> > b/drivers/gpu/drm/i915/intel_cdclk.c
> > index 9c5ceb98d48f..d77e2bec1e29 100644
> > --- a/drivers/gpu/drm/i915/intel_cdclk.c
> > +++ b/drivers/gpu/drm/i915/intel_cdclk.c
> > @@ -931,16 +931,10 @@ static void skl_set_preferred_cdclk_vco(struct
> > drm_i915_private *dev_priv,
> >
> > static void skl_dpll0_enable(struct drm_i915_private *dev_priv, int vco)
> > {
> > - int min_cdclk = skl_calc_cdclk(0, vco);
> > u32 val;
> >
> > WARN_ON(vco != 8100000 && vco != 8640000);
> >
> > - /* select the minimum CDCLK before enabling DPLL 0 */
> > - val = CDCLK_FREQ_337_308 | skl_cdclk_decimal(min_cdclk);
> > - I915_WRITE(CDCLK_CTL, val);
> > - POSTING_READ(CDCLK_CTL);
> > -
> > /*
> > * We always enable DPLL0 with the lowest link rate possible, but
> > still
> > * taking into account the VCO required to operate the eDP panel
> > at the
> > @@ -994,7 +988,7 @@ static void skl_set_cdclk(struct drm_i915_private
> > *dev_priv,
> > {
> > int cdclk = cdclk_state->cdclk;
> > int vco = cdclk_state->vco;
> > - u32 freq_select;
> > + u32 freq_select, cdclk_ctl;
> > int ret;
> >
> > mutex_lock(&dev_priv->pcu_lock);
> > @@ -1009,7 +1003,7 @@ static void skl_set_cdclk(struct drm_i915_private
> > *dev_priv,
> > return;
> > }
> >
> > - /* set CDCLK_CTL */
> > + /* Choose frequency for this cdclk */
> > switch (cdclk) {
> > default:
> > WARN_ON(cdclk != dev_priv->cdclk.hw.ref);
> > @@ -1036,10 +1030,33 @@ static void skl_set_cdclk(struct drm_i915_private
> > *dev_priv,
> > dev_priv->cdclk.hw.vco != vco)
> > skl_dpll0_disable(dev_priv);
> >
> > + cdclk_ctl = I915_READ(CDCLK_CTL);
> > +
> > + if (dev_priv->cdclk.hw.vco != vco) {
> > + /* Wa Display #1183: skl,kbl,cfl */
> > + cdclk_ctl &= ~(CDCLK_FREQ_SEL_MASK |
> > CDCLK_FREQ_DECIMAL_MASK);
> > + cdclk_ctl |= freq_select | skl_cdclk_decimal(cdclk);
> > + I915_WRITE(CDCLK_CTL, cdclk_ctl);
> > + }
> > +
> > + /* Wa Display #1183: skl,kbl,cfl */
> > + cdclk_ctl |= CDCLK_DIVMUX_CD_OVERRIDE;
> > + I915_WRITE(CDCLK_CTL, cdclk_ctl);
> > + POSTING_READ(CDCLK_CTL);
> > +
> > if (dev_priv->cdclk.hw.vco != vco)
> > skl_dpll0_enable(dev_priv, vco);
> >
> > - I915_WRITE(CDCLK_CTL, freq_select | skl_cdclk_decimal(cdclk));
> > + /* Wa Display #1183: skl,kbl,cfl */
> > + cdclk_ctl &= ~(CDCLK_FREQ_SEL_MASK | CDCLK_FREQ_DECIMAL_MASK);
> > + I915_WRITE(CDCLK_CTL, cdclk_ctl);
> > +
> > + cdclk_ctl |= freq_select | skl_cdclk_decimal(cdclk);
> > + I915_WRITE(CDCLK_CTL, cdclk_ctl);
> > +
> > + /* Wa Display #1183: skl,kbl,cfl */
> > + cdclk_ctl &= ~CDCLK_DIVMUX_CD_OVERRIDE;
> > + I915_WRITE(CDCLK_CTL, cdclk_ctl);
> > POSTING_READ(CDCLK_CTL);
> >
> > /* inform PCU of the change */
> > diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c
> > b/drivers/gpu/drm/i915/intel_runtime_pm.c
> > index 8315499452dc..35796fa8e6b4 100644
> > --- a/drivers/gpu/drm/i915/intel_runtime_pm.c
> > +++ b/drivers/gpu/drm/i915/intel_runtime_pm.c
> > @@ -598,6 +598,11 @@ void gen9_enable_dc5(struct drm_i915_private
> > *dev_priv)
> >
> > DRM_DEBUG_KMS("Enabling DC5\n");
> >
> > + /* Wa Display #1183: skl,kbl,cfl */
> > + if (IS_GEN9_BC(dev_priv))
> > + I915_WRITE(GEN8_CHICKEN_DCPR_1,
> > I915_READ(GEN8_CHICKEN_DCPR_1) |
> > + SKL_SELECT_ALTERNATE_DC_EXIT);
> > +
> > gen9_set_dc_state(dev_priv, DC_STATE_EN_UPTO_DC5);
> > }
> >
> > @@ -625,6 +630,11 @@ void skl_disable_dc6(struct drm_i915_private
> > *dev_priv)
> > {
> > DRM_DEBUG_KMS("Disabling DC6\n");
> >
> > + /* Wa Display #1183: skl,kbl,cfl */
> > + if (IS_GEN9_BC(dev_priv))
> > + I915_WRITE(GEN8_CHICKEN_DCPR_1,
> > I915_READ(GEN8_CHICKEN_DCPR_1) |
> > + SKL_SELECT_ALTERNATE_DC_EXIT);
> > +
> > gen9_set_dc_state(dev_priv, DC_STATE_DISABLE);
> > }
> >
> > --
> > 2.14.3
>
>