From 25e0e5ae561003817797c23ae3b85cf510be11c5 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Ville=20Syrj=C3=A4l=C3=A4?= Date: Thu, 17 Nov 2022 15:00:01 -0800 Subject: [PATCH] drm/i915/display: Do both crawl and squash when changing cdclk MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit For MTL, changing cdclk from between certain frequencies has both squash and crawl. Use the current cdclk config and the new(desired) cdclk config to construct a mid cdclk config. Set the cdclk twice: - Current cdclk -> mid cdclk - mid cdclk -> desired cdclk Driver should not take some Pcode mailbox communication in the cdclk path for platforms that are Display version 14 and later. v2: Add check in intel_modeset_calc_cdclk() to avoid cdclk change via modeset for platforms that support squash_crawl sequences(Ville) v3: Add checks for: - scenario where only slow clock is used and cdclk is actually 0 (bringing up display). - PLLs are on before looking up the waveform. - Squash and crawl capability checks.(Ville) v4: Rebase - Move checks to be more consistent (Ville) - Add comments (Bala) v5: - Further small changes. Move checks around. - Make if-else better looking (Ville) v6: MTl should not follow PUnit mailbox communication as the rest of gen11+ platforms.(Anusha) Cc: Clint Taylor Cc: Balasubramani Vivekanandan Signed-off-by: Anusha Srivatsa Signed-off-by: Ville Syrjälä Reviewed-by: Matt Roper Link: https://patchwork.freedesktop.org/patch/msgid/20221117230002.792096-2-anusha.srivatsa@intel.com --- drivers/gpu/drm/i915/display/intel_cdclk.c | 181 ++++++++++++++++++++++++----- 1 file changed, 150 insertions(+), 31 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_cdclk.c b/drivers/gpu/drm/i915/display/intel_cdclk.c index 25d0127..519c1df 100644 --- a/drivers/gpu/drm/i915/display/intel_cdclk.c +++ b/drivers/gpu/drm/i915/display/intel_cdclk.c @@ -1727,37 +1727,79 @@ static bool cdclk_pll_is_unknown(unsigned int vco) return vco == ~0; } -static void bxt_set_cdclk(struct drm_i915_private *dev_priv, - const struct intel_cdclk_config *cdclk_config, - enum pipe pipe) +static int cdclk_squash_divider(u16 waveform) +{ + return hweight16(waveform ?: 0xffff); +} + +static bool cdclk_compute_crawl_and_squash_midpoint(struct drm_i915_private *i915, + const struct intel_cdclk_config *old_cdclk_config, + const struct intel_cdclk_config *new_cdclk_config, + struct intel_cdclk_config *mid_cdclk_config) +{ + u16 old_waveform, new_waveform, mid_waveform; + int size = 16; + int div = 2; + + /* Return if PLL is in an unknown state, force a complete disable and re-enable. */ + if (cdclk_pll_is_unknown(old_cdclk_config->vco)) + return false; + + /* Return if both Squash and Crawl are not present */ + if (!HAS_CDCLK_CRAWL(i915) || !HAS_CDCLK_SQUASH(i915)) + return false; + + old_waveform = cdclk_squash_waveform(i915, old_cdclk_config->cdclk); + new_waveform = cdclk_squash_waveform(i915, new_cdclk_config->cdclk); + + /* Return if Squash only or Crawl only is the desired action */ + if (old_cdclk_config->vco == 0 || new_cdclk_config->vco == 0 || + old_cdclk_config->vco == new_cdclk_config->vco || + old_waveform == new_waveform) + return false; + + *mid_cdclk_config = *new_cdclk_config; + + /* + * Populate the mid_cdclk_config accordingly. + * - If moving to a higher cdclk, the desired action is squashing. + * The mid cdclk config should have the new (squash) waveform. + * - If moving to a lower cdclk, the desired action is crawling. + * The mid cdclk config should have the new vco. + */ + + if (cdclk_squash_divider(new_waveform) > cdclk_squash_divider(old_waveform)) { + mid_cdclk_config->vco = old_cdclk_config->vco; + mid_waveform = new_waveform; + } else { + mid_cdclk_config->vco = new_cdclk_config->vco; + mid_waveform = old_waveform; + } + + mid_cdclk_config->cdclk = DIV_ROUND_CLOSEST(cdclk_squash_divider(mid_waveform) * + mid_cdclk_config->vco, size * div); + + /* make sure the mid clock came out sane */ + + drm_WARN_ON(&i915->drm, mid_cdclk_config->cdclk < + min(old_cdclk_config->cdclk, new_cdclk_config->cdclk)); + drm_WARN_ON(&i915->drm, mid_cdclk_config->cdclk > + i915->display.cdclk.max_cdclk_freq); + drm_WARN_ON(&i915->drm, cdclk_squash_waveform(i915, mid_cdclk_config->cdclk) != + mid_waveform); + + return true; +} + +static void _bxt_set_cdclk(struct drm_i915_private *dev_priv, + const struct intel_cdclk_config *cdclk_config, + enum pipe pipe) { int cdclk = cdclk_config->cdclk; int vco = cdclk_config->vco; u32 val; u16 waveform; int clock; - int ret; - - /* Inform power controller of upcoming frequency change. */ - if (DISPLAY_VER(dev_priv) >= 11) - ret = skl_pcode_request(&dev_priv->uncore, SKL_PCODE_CDCLK_CONTROL, - SKL_CDCLK_PREPARE_FOR_CHANGE, - SKL_CDCLK_READY_FOR_CHANGE, - SKL_CDCLK_READY_FOR_CHANGE, 3); - else - /* - * BSpec requires us to wait up to 150usec, but that leads to - * timeouts; the 2ms used here is based on experiment. - */ - ret = snb_pcode_write_timeout(&dev_priv->uncore, - HSW_PCODE_DE_WRITE_FREQ_REQ, - 0x80000000, 150, 2); - if (ret) { - drm_err(&dev_priv->drm, - "Failed to inform PCU about cdclk change (err %d, freq %d)\n", - ret, cdclk); - return; - } if (HAS_CDCLK_CRAWL(dev_priv) && dev_priv->display.cdclk.hw.vco > 0 && vco > 0 && !cdclk_pll_is_unknown(dev_priv->display.cdclk.hw.vco)) { @@ -1793,11 +1835,62 @@ static void bxt_set_cdclk(struct drm_i915_private *dev_priv, if (pipe != INVALID_PIPE) intel_crtc_wait_for_next_vblank(intel_crtc_for_pipe(dev_priv, pipe)); +} + +static void bxt_set_cdclk(struct drm_i915_private *dev_priv, + const struct intel_cdclk_config *cdclk_config, + enum pipe pipe) +{ + struct intel_cdclk_config mid_cdclk_config; + int cdclk = cdclk_config->cdclk; + int ret = 0; + + /* + * Inform power controller of upcoming frequency change. + * Display versions 14 and beyond do not follow the PUnit + * mailbox communication, skip + * this step. + */ + if (DISPLAY_VER(dev_priv) >= 14) + /* NOOP */; + else if (DISPLAY_VER(dev_priv) >= 11) + ret = skl_pcode_request(&dev_priv->uncore, SKL_PCODE_CDCLK_CONTROL, + SKL_CDCLK_PREPARE_FOR_CHANGE, + SKL_CDCLK_READY_FOR_CHANGE, + SKL_CDCLK_READY_FOR_CHANGE, 3); + else + /* + * BSpec requires us to wait up to 150usec, but that leads to + * timeouts; the 2ms used here is based on experiment. + */ + ret = snb_pcode_write_timeout(&dev_priv->uncore, + HSW_PCODE_DE_WRITE_FREQ_REQ, + 0x80000000, 150, 2); + + if (ret) { + drm_err(&dev_priv->drm, + "Failed to inform PCU about cdclk change (err %d, freq %d)\n", + ret, cdclk); + return; + } - if (DISPLAY_VER(dev_priv) >= 11) { + if (cdclk_compute_crawl_and_squash_midpoint(dev_priv, &dev_priv->display.cdclk.hw, + cdclk_config, &mid_cdclk_config)) { + _bxt_set_cdclk(dev_priv, &mid_cdclk_config, pipe); + _bxt_set_cdclk(dev_priv, cdclk_config, pipe); + } else { + _bxt_set_cdclk(dev_priv, cdclk_config, pipe); + } + + if (DISPLAY_VER(dev_priv) >= 14) + /* + * NOOP - No Pcode communication needed for + * Display versions 14 and beyond + */; + else if (DISPLAY_VER(dev_priv) >= 11) ret = snb_pcode_write(&dev_priv->uncore, SKL_PCODE_CDCLK_CONTROL, cdclk_config->voltage_level); - } else { + else /* * The timeout isn't specified, the 2ms used here is based on * experiment. @@ -1808,7 +1901,6 @@ static void bxt_set_cdclk(struct drm_i915_private *dev_priv, HSW_PCODE_DE_WRITE_FREQ_REQ, cdclk_config->voltage_level, 150, 2); - } if (ret) { drm_err(&dev_priv->drm, @@ -1965,6 +2057,28 @@ void intel_cdclk_uninit_hw(struct drm_i915_private *i915) skl_cdclk_uninit_hw(i915); } +static bool intel_cdclk_can_crawl_and_squash(struct drm_i915_private *i915, + const struct intel_cdclk_config *a, + const struct intel_cdclk_config *b) +{ + u16 old_waveform; + u16 new_waveform; + + drm_WARN_ON(&i915->drm, cdclk_pll_is_unknown(a->vco)); + + if (a->vco == 0 || b->vco == 0) + return false; + + if (!HAS_CDCLK_CRAWL(i915) || !HAS_CDCLK_SQUASH(i915)) + return false; + + old_waveform = cdclk_squash_waveform(i915, a->cdclk); + new_waveform = cdclk_squash_waveform(i915, b->cdclk); + + return a->vco != b->vco && + old_waveform != new_waveform; +} + static bool intel_cdclk_can_crawl(struct drm_i915_private *dev_priv, const struct intel_cdclk_config *a, const struct intel_cdclk_config *b) @@ -2771,9 +2885,14 @@ int intel_modeset_calc_cdclk(struct intel_atomic_state *state) pipe = INVALID_PIPE; } - if (intel_cdclk_can_squash(dev_priv, - &old_cdclk_state->actual, - &new_cdclk_state->actual)) { + if (intel_cdclk_can_crawl_and_squash(dev_priv, + &old_cdclk_state->actual, + &new_cdclk_state->actual)) { + drm_dbg_kms(&dev_priv->drm, + "Can change cdclk via crawling and squashing\n"); + } else if (intel_cdclk_can_squash(dev_priv, + &old_cdclk_state->actual, + &new_cdclk_state->actual)) { drm_dbg_kms(&dev_priv->drm, "Can change cdclk via squashing\n"); } else if (intel_cdclk_can_crawl(dev_priv, -- 2.7.4