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.
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
