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[SRU,B/OEM-B] drm/i915: Force 2*96 MHz cdclk on glk/cnl when audio power is enabled

Message ID 20190603060705.10776-2-hui.wang@canonical.com
State Rejected
Headers show
Series [SRU,B/OEM-B] drm/i915: Force 2*96 MHz cdclk on glk/cnl when audio power is enabled | expand

Commit Message

Hui Wang June 3, 2019, 6:07 a.m. UTC
From: Ville Syrjälä <ville.syrjala@linux.intel.com>

BugLink: https://launchpad.net/bugs/1826868

CDCLK has to be at least twice the BLCK regardless of audio. Audio
driver has to probe using this hook and increase the clock even in
absence of any display.

v2: Use atomic refcount for get_power, put_power so that we can
    call each once(Abhay).
v3: Reset power well 2 to avoid any transaction on iDisp link
    during cdclk change(Abhay).
v4: Remove Power well 2 reset workaround(Ville).
v5: Remove unwanted Power well 2 register defined in v4(Abhay).
v6:
- Use a dedicated flag instead of state->modeset for min CDCLK changes
- Make get/put audio power domain symmetric
- Rebased on top of intel_wakeref tracking changes.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Abhay Kumar <abhay.kumar@intel.com>
Tested-by: Abhay Kumar <abhay.kumar@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Clint Taylor <Clinton.A.Taylor@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190320135439.12201-1-imre.deak@intel.com
(backported from commit 905801fe72377b4dc53c6e13eea1a91c6a4aa0c4)
Signed-off-by: Hui Wang <hui.wang@canonical.com>
---
 drivers/gpu/drm/i915/i915_drv.h      |  3 ++
 drivers/gpu/drm/i915/intel_audio.c   | 57 ++++++++++++++++++++++++++++
 drivers/gpu/drm/i915/intel_cdclk.c   | 28 +++++---------
 drivers/gpu/drm/i915/intel_display.c | 10 ++++-
 drivers/gpu/drm/i915/intel_drv.h     |  3 ++
 5 files changed, 81 insertions(+), 20 deletions(-)
diff mbox series

Patch

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 706a2bc5f37d..eaba810a928e 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2358,6 +2358,8 @@  struct drm_i915_private {
 		struct intel_cdclk_state actual;
 		/* The current hardware cdclk state */
 		struct intel_cdclk_state hw;
+
+		int force_min_cdclk;
 	} cdclk;
 
 	/**
@@ -2478,6 +2480,7 @@  struct drm_i915_private {
 	 *
 	 */
 	struct mutex av_mutex;
+	int audio_power_refcount;
 
 	struct {
 		struct list_head list;
diff --git a/drivers/gpu/drm/i915/intel_audio.c b/drivers/gpu/drm/i915/intel_audio.c
index d1a8c0fa2d38..0d9c65f40116 100644
--- a/drivers/gpu/drm/i915/intel_audio.c
+++ b/drivers/gpu/drm/i915/intel_audio.c
@@ -688,13 +688,70 @@  void intel_init_audio_hooks(struct drm_i915_private *dev_priv)
 	}
 }
 
+static void glk_force_audio_cdclk(struct drm_i915_private *dev_priv,
+				  bool enable)
+{
+	struct drm_modeset_acquire_ctx ctx;
+	struct drm_atomic_state *state;
+	int ret;
+
+	drm_modeset_acquire_init(&ctx, 0);
+	state = drm_atomic_state_alloc(&dev_priv->drm);
+	if (WARN_ON(!state))
+		return;
+
+	state->acquire_ctx = &ctx;
+
+ retry:
+	to_intel_atomic_state(state)->cdclk.force_min_cdclk_changed = true;
+	to_intel_atomic_state(state)->cdclk.force_min_cdclk =
+		enable ? 2 * 96000 : 0;
+
+	/*
+	 * Protects dev_priv->cdclk.force_min_cdclk
+	 * Need to lock this here in case we have no active pipes
+	 * and thus wouldn't lock it during the commit otherwise.
+	 */
+	ret = drm_modeset_lock(&dev_priv->drm.mode_config.connection_mutex,
+			       &ctx);
+	if (!ret)
+		ret = drm_atomic_commit(state);
+
+	if (ret == -EDEADLK) {
+		drm_atomic_state_clear(state);
+		drm_modeset_backoff(&ctx);
+		goto retry;
+	}
+
+	WARN_ON(ret);
+
+	drm_atomic_state_put(state);
+
+	drm_modeset_drop_locks(&ctx);
+	drm_modeset_acquire_fini(&ctx);
+}
+
 static void i915_audio_component_get_power(struct device *kdev)
 {
+	struct drm_i915_private *dev_priv = kdev_to_i915(kdev);
 	intel_display_power_get(kdev_to_i915(kdev), POWER_DOMAIN_AUDIO);
+
+	/* Force CDCLK to 2*BCLK as long as we need audio to be powered. */
+	if (dev_priv->audio_power_refcount++ == 0)
+		if (IS_CANNONLAKE(dev_priv) || IS_GEMINILAKE(dev_priv))
+			glk_force_audio_cdclk(dev_priv, true);
+
 }
 
 static void i915_audio_component_put_power(struct device *kdev)
 {
+	struct drm_i915_private *dev_priv = kdev_to_i915(kdev);
+
+	/* Stop forcing CDCLK to 2*BCLK if no need for audio to be powered. */
+	if (--dev_priv->audio_power_refcount == 0)
+		if (IS_CANNONLAKE(dev_priv) || IS_GEMINILAKE(dev_priv))
+			glk_force_audio_cdclk(dev_priv, false);
+
 	intel_display_power_put(kdev_to_i915(kdev), POWER_DOMAIN_AUDIO);
 }
 
diff --git a/drivers/gpu/drm/i915/intel_cdclk.c b/drivers/gpu/drm/i915/intel_cdclk.c
index 2f678aff46f8..cb23023d9da1 100644
--- a/drivers/gpu/drm/i915/intel_cdclk.c
+++ b/drivers/gpu/drm/i915/intel_cdclk.c
@@ -1819,19 +1819,8 @@  int intel_crtc_compute_min_cdclk(const struct intel_crtc_state *crtc_state)
 	/*
 	 * According to BSpec, "The CD clock frequency must be at least twice
 	 * the frequency of the Azalia BCLK." and BCLK is 96 MHz by default.
-	 *
-	 * FIXME: Check the actual, not default, BCLK being used.
-	 *
-	 * FIXME: This does not depend on ->has_audio because the higher CDCLK
-	 * is required for audio probe, also when there are no audio capable
-	 * displays connected at probe time. This leads to unnecessarily high
-	 * CDCLK when audio is not required.
-	 *
-	 * FIXME: This limit is only applied when there are displays connected
-	 * at probe time. If we probe without displays, we'll still end up using
-	 * the platform minimum CDCLK, failing audio probe.
 	 */
-	if (INTEL_GEN(dev_priv) >= 9)
+	if (crtc_state->has_audio && INTEL_GEN(dev_priv) >= 9)
 		min_cdclk = max(2 * 96000, min_cdclk);
 
 	if (min_cdclk > dev_priv->max_cdclk_freq) {
@@ -1863,7 +1852,7 @@  static int intel_compute_min_cdclk(struct drm_atomic_state *state)
 		intel_state->min_cdclk[i] = min_cdclk;
 	}
 
-	min_cdclk = 0;
+	min_cdclk = intel_state->cdclk.force_min_cdclk;
 	for_each_pipe(dev_priv, pipe)
 		min_cdclk = max(intel_state->min_cdclk[pipe], min_cdclk);
 
@@ -1885,7 +1874,8 @@  static int vlv_modeset_calc_cdclk(struct drm_atomic_state *state)
 	intel_state->cdclk.logical.cdclk = cdclk;
 
 	if (!intel_state->active_crtcs) {
-		cdclk = vlv_calc_cdclk(dev_priv, 0);
+		cdclk = vlv_calc_cdclk(dev_priv,
+				       intel_state->cdclk.force_min_cdclk);
 
 		intel_state->cdclk.actual.cdclk = cdclk;
 	} else {
@@ -1914,7 +1904,7 @@  static int bdw_modeset_calc_cdclk(struct drm_atomic_state *state)
 	intel_state->cdclk.logical.cdclk = cdclk;
 
 	if (!intel_state->active_crtcs) {
-		cdclk = bdw_calc_cdclk(0);
+		cdclk = bdw_calc_cdclk(intel_state->cdclk.force_min_cdclk);
 
 		intel_state->cdclk.actual.cdclk = cdclk;
 	} else {
@@ -1982,7 +1972,7 @@  static int skl_modeset_calc_cdclk(struct drm_atomic_state *state)
 	intel_state->cdclk.logical.cdclk = cdclk;
 
 	if (!intel_state->active_crtcs) {
-		cdclk = skl_calc_cdclk(0, vco);
+		cdclk = skl_calc_cdclk(intel_state->cdclk.force_min_cdclk, vco);
 
 		intel_state->cdclk.actual.vco = vco;
 		intel_state->cdclk.actual.cdclk = cdclk;
@@ -2017,10 +2007,10 @@  static int bxt_modeset_calc_cdclk(struct drm_atomic_state *state)
 
 	if (!intel_state->active_crtcs) {
 		if (IS_GEMINILAKE(dev_priv)) {
-			cdclk = glk_calc_cdclk(0);
+			cdclk = glk_calc_cdclk(intel_state->cdclk.force_min_cdclk);
 			vco = glk_de_pll_vco(dev_priv, cdclk);
 		} else {
-			cdclk = bxt_calc_cdclk(0);
+			cdclk = bxt_calc_cdclk(intel_state->cdclk.force_min_cdclk);
 			vco = bxt_de_pll_vco(dev_priv, cdclk);
 		}
 
@@ -2051,7 +2041,7 @@  static int cnl_modeset_calc_cdclk(struct drm_atomic_state *state)
 	intel_state->cdclk.logical.cdclk = cdclk;
 
 	if (!intel_state->active_crtcs) {
-		cdclk = cnl_calc_cdclk(0);
+		cdclk = cnl_calc_cdclk(intel_state->cdclk.force_min_cdclk);
 		vco = cnl_cdclk_pll_vco(dev_priv, cdclk);
 
 		intel_state->cdclk.actual.vco = vco;
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 8544de5ba687..b474d2d3e9ba 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -11924,6 +11924,12 @@  static int intel_modeset_checks(struct drm_atomic_state *state)
 		return -EINVAL;
 	}
 
+	/* keep the current setting */
+	if (!intel_state->cdclk.force_min_cdclk_changed)
+		intel_state->cdclk.force_min_cdclk =
+			dev_priv->cdclk.force_min_cdclk;
+
+
 	intel_state->modeset = true;
 	intel_state->active_crtcs = dev_priv->active_crtcs;
 	intel_state->cdclk.logical = dev_priv->cdclk.logical;
@@ -12016,7 +12022,7 @@  static int intel_atomic_check(struct drm_device *dev,
 	struct drm_crtc *crtc;
 	struct drm_crtc_state *old_crtc_state, *crtc_state;
 	int ret, i;
-	bool any_ms = false;
+	bool any_ms = intel_state->cdclk.force_min_cdclk_changed;
 
 	ret = drm_atomic_helper_check_modeset(dev, state);
 	if (ret)
@@ -12545,6 +12551,8 @@  static int intel_atomic_commit(struct drm_device *dev,
 		dev_priv->active_crtcs = intel_state->active_crtcs;
 		dev_priv->cdclk.logical = intel_state->cdclk.logical;
 		dev_priv->cdclk.actual = intel_state->cdclk.actual;
+		dev_priv->cdclk.force_min_cdclk =
+			intel_state->cdclk.force_min_cdclk;
 	}
 
 	drm_atomic_state_get(state);
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index bfffe27d887a..db287fbe9abc 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -368,6 +368,9 @@  struct intel_atomic_state {
 		 * state only when all crtc's are DPMS off.
 		 */
 		struct intel_cdclk_state actual;
+
+		int force_min_cdclk;
+		bool force_min_cdclk_changed;
 	} cdclk;
 
 	bool dpll_set, modeset;