On Mon, Jan 23, 2023 at 02:52:37PM -0500, Rodrigo Vivi wrote:
> On Mon, Jan 23, 2023 at 03:16:11PM +0200, Stanislav Lisovskiy wrote:
> > It was reported that we might get a hung and loss of register access in
> > some cases when CDCLK PLL is disabled and then enabled, while squashing
> > is enabled.
> > As a workaround it was proposed by HW team that SW should disable squashing
> > when CDCLK PLL is being reenabled.
>
> What's the WA lineage for this WA?
Not sure, what you mean but HSD is: 14017300873
Stan
>
> >
> > Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy@xxxxxxxxx>
> > ---
> > drivers/gpu/drm/i915/display/intel_cdclk.c | 14 ++++++++++++--
> > 1 file changed, 12 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/display/intel_cdclk.c b/drivers/gpu/drm/i915/display/intel_cdclk.c
> > index 0c107a38f9d0..e338f288c9ac 100644
> > --- a/drivers/gpu/drm/i915/display/intel_cdclk.c
> > +++ b/drivers/gpu/drm/i915/display/intel_cdclk.c
> > @@ -1801,6 +1801,13 @@ static bool cdclk_compute_crawl_and_squash_midpoint(struct drm_i915_private *i91
> > return true;
> > }
> >
> > +static bool pll_enable_wa_needed(struct drm_i915_private *dev_priv)
> > +{
> > + return ((IS_DG2(dev_priv) || IS_METEORLAKE(dev_priv))
> > + && dev_priv->display.cdclk.hw.vco > 0
> > + && HAS_CDCLK_SQUASH(dev_priv));
> > +}
> > +
> > static void _bxt_set_cdclk(struct drm_i915_private *dev_priv,
> > const struct intel_cdclk_config *cdclk_config,
> > enum pipe pipe)
> > @@ -1815,9 +1822,12 @@ static void _bxt_set_cdclk(struct drm_i915_private *dev_priv,
> > !cdclk_pll_is_unknown(dev_priv->display.cdclk.hw.vco)) {
> > if (dev_priv->display.cdclk.hw.vco != vco)
> > adlp_cdclk_pll_crawl(dev_priv, vco);
> > - } else if (DISPLAY_VER(dev_priv) >= 11)
> > + } else if (DISPLAY_VER(dev_priv) >= 11) {
> > + if (pll_enable_wa_needed(dev_priv))
> > + dg2_cdclk_squash_program(dev_priv, 0);
> > +
> > icl_cdclk_pll_update(dev_priv, vco);
> > - else
> > + } else
> > bxt_cdclk_pll_update(dev_priv, vco);
> >
> > waveform = cdclk_squash_waveform(dev_priv, cdclk);
> > --
> > 2.37.3
> >
