From: Stanislav Lisovskiy Date: Mon, 30 Jan 2023 13:58:36 +0000 (+0200) Subject: drm/i915: Implement workaround for CDCLK PLL disable/enable X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=33d0c67dcbb045cbbbba9d41fa6e4b1f73bf3888;p=linux.git drm/i915: Implement workaround for CDCLK PLL disable/enable 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. v2: - Added WA number comment(Rodrigo Vivi) Signed-off-by: Stanislav Lisovskiy Reviewed-by: Anusha Srivatsa Link: https://patchwork.freedesktop.org/patch/msgid/20230130135836.12738-1-stanislav.lisovskiy@intel.com --- diff --git a/drivers/gpu/drm/i915/display/intel_cdclk.c b/drivers/gpu/drm/i915/display/intel_cdclk.c index 7e16b655c8338..82da76b586edb 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 +1822,13 @@ 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) { + /* wa_15010685871: dg2, mtl */ + 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);