[Intel-gfx] [PATCH] drm/i915: Control PSR at runtime through debugfs only

Maarten Lankhorst maarten.lankhorst at linux.intel.com
Wed Mar 14 11:46:58 UTC 2018


Allow controlling link status through i915_edp_psr_status, in the same way kernel does.
This replaces changing the module parameter at runtime, then forcing a modeset.

Writing -1 restores the original PSR mode set through the module parameter.
Writing 0 disables PSR.
Writing 1 enables PSR with default link standby mode.
Writing 2 enables PSR with link standby.
Writing 3 enables PSR with link standby disabled.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
---
This breaks kms_frontbuffer_tracking, and needs the following patch to work:
https://patchwork.freedesktop.org/patch/209956/

XXX: Make global_enable a tristate, to keep older versions of kms_frontbuffer_tracking working?

 drivers/gpu/drm/i915/i915_debugfs.c | 182 +++++++++++++++++++++++++++++++++++-
 drivers/gpu/drm/i915/i915_drv.h     |   2 +
 drivers/gpu/drm/i915/i915_params.c  |   2 +-
 drivers/gpu/drm/i915/intel_drv.h    |   7 ++
 drivers/gpu/drm/i915/intel_psr.c    | 139 ++++++++++++++++-----------
 5 files changed, 271 insertions(+), 61 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 574fcf234007..534a3b04e6a3 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -2546,16 +2546,13 @@ static const char *psr2_live_status(u32 val)
 
 static int i915_edp_psr_status(struct seq_file *m, void *data)
 {
-	struct drm_i915_private *dev_priv = node_to_i915(m->private);
+	struct drm_i915_private *dev_priv = m->private;
 	u32 psrperf = 0;
 	u32 stat[3];
 	enum pipe pipe;
 	bool enabled = false;
 	bool sink_support;
 
-	if (!HAS_PSR(dev_priv))
-		return -ENODEV;
-
 	sink_support = dev_priv->psr.sink_support;
 	seq_printf(m, "Sink_Support: %s\n", yesno(sink_support));
 	if (!sink_support)
@@ -2631,6 +2628,181 @@ static int i915_edp_psr_status(struct seq_file *m, void *data)
 	return 0;
 }
 
+static bool psr_needs_disable(struct drm_i915_private *dev_priv,
+			      bool enable, bool link_standby)
+{
+	if (!dev_priv->psr.global_enable)
+		return false;
+
+	if (!enable)
+		return true;
+
+	if (dev_priv->psr.link_standby != link_standby)
+		return true;
+
+	return false;
+}
+
+static bool psr_needs_enable(struct drm_i915_private *dev_priv,
+			     bool enable)
+{
+	if (!enable)
+		return false;
+
+	return !dev_priv->psr.global_enable;
+}
+
+static int __i915_edp_psr_write(struct drm_i915_private *dev_priv,
+				struct drm_modeset_acquire_ctx *ctx,
+				bool enable, bool link_standby)
+{
+	struct drm_device *dev = &dev_priv->drm;
+	struct drm_connector_list_iter conn_iter;
+	struct drm_connector *connector;
+	struct drm_encoder *encoder;
+	struct drm_crtc *crtc;
+	int ret;
+	bool needs_enable, found;
+
+	ret = drm_modeset_lock(&dev->mode_config.connection_mutex, ctx);
+	if (ret)
+		return ret;
+
+	mutex_lock(&dev_priv->psr.lock);
+retry:
+	if (!dev_priv->psr.enabled) {
+		dev_priv->psr.global_enable = enable;
+		dev_priv->psr.link_standby = link_standby;
+		goto end;
+	}
+	encoder = &dp_to_dig_port(dev_priv->psr.enabled)->base.base;
+	mutex_unlock(&dev_priv->psr.lock);
+
+	found = false;
+	drm_connector_list_iter_begin(dev, &conn_iter);
+	drm_for_each_connector_iter(connector, &conn_iter)
+		if (connector->state->best_encoder == encoder) {
+			found = true;
+			break;
+		}
+	drm_connector_list_iter_end(&conn_iter);
+
+	if (WARN_ON(!found))
+		return -EINVAL;
+
+	crtc = connector->state->crtc;
+	ret = drm_modeset_lock(&crtc->mutex, ctx);
+	if (ret)
+		return ret;
+
+	mutex_lock(&dev_priv->psr.lock);
+	if (dev_priv->psr.enabled != enc_to_intel_dp(encoder))
+		goto retry;
+
+	if ((connector->state->commit && !try_wait_for_completion(&connector->state->commit->hw_done)) ||
+	    (crtc->state->commit && !try_wait_for_completion(&crtc->state->commit->hw_done))) {
+		ret = -EBUSY;
+		goto end;
+	}
+
+	if (psr_needs_disable(dev_priv, enable, link_standby)) {
+		__intel_psr_disable(dev_priv, dev_priv->psr.enabled, to_intel_crtc_state(crtc->state));
+		dev_priv->psr.global_enable = false;
+	}
+
+	needs_enable = psr_needs_enable(dev_priv, enable);
+	dev_priv->psr.global_enable = enable;
+	dev_priv->psr.link_standby = link_standby;
+
+	if (needs_enable)
+		__intel_psr_enable(dev_priv, dev_priv->psr.enabled, to_intel_crtc_state(crtc->state));
+
+end:
+	mutex_unlock(&dev_priv->psr.lock);
+	return ret;
+}
+
+static ssize_t i915_edp_psr_write(struct file *file, const char __user *ubuf,
+				  size_t len, loff_t *offp)
+{
+	struct seq_file *m = file->private_data;
+	struct drm_i915_private *dev_priv = m->private;
+	struct drm_modeset_acquire_ctx ctx;
+	int ret, val;
+	bool link_standby;
+
+	if (!dev_priv->psr.sink_support)
+		return -ENODEV;
+
+	ret = kstrtoint_from_user(ubuf, len, 10, &val);
+	if (ret < 0) {
+		bool enable;
+		ret = kstrtobool_from_user(ubuf, len, &enable);
+
+		if (ret < 0)
+			return ret;
+
+		val = enable;
+	}
+
+	/* -1 -> reset to default */
+	if (val == -1)
+		val = i915_modparams.enable_psr;
+
+	switch (val) {
+	case 0:
+	case 1:
+		link_standby = intel_psr_default_link_standby(dev_priv);
+		break;
+	case 2:
+		link_standby = true;
+		break;
+	case 3:
+		link_standby = false;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	intel_runtime_pm_get(dev_priv);
+
+	drm_modeset_acquire_init(&ctx, DRM_MODESET_ACQUIRE_INTERRUPTIBLE);
+
+retry:
+	ret = __i915_edp_psr_write(dev_priv, &ctx, val, link_standby);
+	if (ret == -EBUSY) {
+		ret = drm_modeset_backoff(&ctx);
+		if (!ret)
+			goto retry;
+	}
+
+	drm_modeset_drop_locks(&ctx);
+	drm_modeset_acquire_fini(&ctx);
+
+	intel_runtime_pm_put(dev_priv);
+
+	return ret ?: len;
+}
+
+static int i915_edp_psr_open(struct inode *inode, struct file *file)
+{
+	struct drm_i915_private *dev_priv = inode->i_private;
+
+	if (!HAS_PSR(dev_priv))
+		return -ENODEV;
+
+	return single_open(file, i915_edp_psr_status, dev_priv);
+}
+
+static const struct file_operations i915_edp_psr_ops = {
+	.owner = THIS_MODULE,
+	.open = i915_edp_psr_open,
+	.read = seq_read,
+	.llseek = seq_lseek,
+	.release = single_release,
+	.write = i915_edp_psr_write
+};
+
 static int i915_sink_crc(struct seq_file *m, void *data)
 {
 	struct drm_i915_private *dev_priv = node_to_i915(m->private);
@@ -4734,7 +4906,6 @@ static const struct drm_info_list i915_debugfs_list[] = {
 	{"i915_swizzle_info", i915_swizzle_info, 0},
 	{"i915_ppgtt_info", i915_ppgtt_info, 0},
 	{"i915_llc", i915_llc, 0},
-	{"i915_edp_psr_status", i915_edp_psr_status, 0},
 	{"i915_sink_crc_eDP1", i915_sink_crc, 0},
 	{"i915_energy_uJ", i915_energy_uJ, 0},
 	{"i915_runtime_pm_status", i915_runtime_pm_status, 0},
@@ -4761,6 +4932,7 @@ static const struct i915_debugfs_files {
 	{"i915_wedged", &i915_wedged_fops},
 	{"i915_max_freq", &i915_max_freq_fops},
 	{"i915_min_freq", &i915_min_freq_fops},
+	{"i915_edp_psr_status", &i915_edp_psr_ops},
 	{"i915_cache_sharing", &i915_cache_sharing_fops},
 	{"i915_ring_missed_irq", &i915_ring_missed_irq_fops},
 	{"i915_ring_test_irq", &i915_ring_test_irq_fops},
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index b39c5f68efb2..dbc9c062c658 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -608,6 +608,8 @@ struct i915_psr {
 	bool alpm;
 	bool has_hw_tracking;
 
+	bool global_enable;
+
 	void (*enable_source)(struct intel_dp *,
 			      const struct intel_crtc_state *);
 	void (*disable_source)(struct intel_dp *,
diff --git a/drivers/gpu/drm/i915/i915_params.c b/drivers/gpu/drm/i915/i915_params.c
index 08108ce5be21..0d02980b3a2c 100644
--- a/drivers/gpu/drm/i915/i915_params.c
+++ b/drivers/gpu/drm/i915/i915_params.c
@@ -90,7 +90,7 @@ i915_param_named_unsafe(enable_ppgtt, int, 0400,
 	"Override PPGTT usage. "
 	"(-1=auto [default], 0=disabled, 1=aliasing, 2=full, 3=full with extended address space)");
 
-i915_param_named_unsafe(enable_psr, int, 0600,
+i915_param_named_unsafe(enable_psr, int, 0400,
 	"Enable PSR "
 	"(0=disabled, 1=enabled - link mode chosen per-platform, 2=force link-standby mode, 3=force link-off mode) "
 	"Default: -1 (use per-chip default)");
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 1f0e8f1e4594..c486090f4f52 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -1871,11 +1871,18 @@ bool is_hdcp_supported(struct drm_i915_private *dev_priv, enum port port);
 
 /* intel_psr.c */
 #define CAN_PSR(dev_priv) (HAS_PSR(dev_priv) && dev_priv->psr.sink_support)
+bool intel_psr_default_link_standby(struct drm_i915_private *dev_priv);
 void intel_psr_init_dpcd(struct intel_dp *intel_dp);
 void intel_psr_enable(struct intel_dp *intel_dp,
 		      const struct intel_crtc_state *crtc_state);
+void __intel_psr_enable(struct drm_i915_private *dev_priv,
+			struct intel_dp *intel_dp,
+			const struct intel_crtc_state *crtc_state);
 void intel_psr_disable(struct intel_dp *intel_dp,
 		      const struct intel_crtc_state *old_crtc_state);
+void __intel_psr_disable(struct drm_i915_private *dev_priv,
+			 struct intel_dp *intel_dp,
+			 const struct intel_crtc_state *old_crtc_state);
 void intel_psr_invalidate(struct drm_i915_private *dev_priv,
 			  unsigned frontbuffer_bits,
 			  enum fb_op_origin origin);
diff --git a/drivers/gpu/drm/i915/intel_psr.c b/drivers/gpu/drm/i915/intel_psr.c
index 317cb4a12693..7f59faef7ea7 100644
--- a/drivers/gpu/drm/i915/intel_psr.c
+++ b/drivers/gpu/drm/i915/intel_psr.c
@@ -56,6 +56,36 @@
 #include "intel_drv.h"
 #include "i915_drv.h"
 
+bool intel_psr_default_link_standby(struct drm_i915_private *dev_priv)
+{
+	/* Override link_standby x link_off defaults */
+	if (i915_modparams.enable_psr == 2) {
+		DRM_DEBUG_KMS("PSR: Forcing link standby\n");
+		return true;
+	}
+
+	if (i915_modparams.enable_psr == 3) {
+		DRM_DEBUG_KMS("PSR: Forcing main link off\n");
+		return false;
+	}
+
+	/* Set link_standby x link_off defaults */
+	if (IS_HASWELL(dev_priv) || IS_BROADWELL(dev_priv))
+		/* HSW and BDW require workarounds that we don't implement. */
+		return false;
+	else if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))
+		/* On VLV and CHV only standby mode is supported. */
+		return true;
+	else
+		/* For new platforms let's respect VBT back again */
+		return dev_priv->vbt.psr.full_link;
+}
+
+static bool intel_psr_enabled(struct drm_i915_private *dev_priv)
+{
+	return dev_priv->psr.enabled && dev_priv->psr.global_enable;
+}
+
 static inline enum intel_display_power_domain
 psr_aux_domain(struct intel_dp *intel_dp)
 {
@@ -502,11 +532,6 @@ void intel_psr_compute_config(struct intel_dp *intel_dp,
 	if (!CAN_PSR(dev_priv))
 		return;
 
-	if (!i915_modparams.enable_psr) {
-		DRM_DEBUG_KMS("PSR disable by flag\n");
-		return;
-	}
-
 	/*
 	 * HSW spec explicitly says PSR is tied to port A.
 	 * BDW+ platforms with DDI implementation of PSR have different
@@ -559,7 +584,11 @@ void intel_psr_compute_config(struct intel_dp *intel_dp,
 
 	crtc_state->has_psr = true;
 	crtc_state->has_psr2 = intel_psr2_config_valid(intel_dp, crtc_state);
-	DRM_DEBUG_KMS("Enabling PSR%s\n", crtc_state->has_psr2 ? "2" : "");
+
+	if (dev_priv->psr.global_enable)
+		DRM_DEBUG_KMS("Enabling PSR%s\n", crtc_state->has_psr2 ? "2" : "");
+	else
+		DRM_DEBUG_KMS("PSR disable by flag\n");
 }
 
 static void intel_psr_activate(struct intel_dp *intel_dp)
@@ -617,6 +646,32 @@ static void hsw_psr_enable_source(struct intel_dp *intel_dp,
 	}
 }
 
+void __intel_psr_enable(struct drm_i915_private *dev_priv,
+			struct intel_dp *intel_dp,
+			const struct intel_crtc_state *crtc_state)
+{
+	dev_priv->psr.setup_vsc(intel_dp, crtc_state);
+	dev_priv->psr.enable_sink(intel_dp);
+	dev_priv->psr.enable_source(intel_dp, crtc_state);
+
+	if (INTEL_GEN(dev_priv) >= 9) {
+		intel_psr_activate(intel_dp);
+	} else {
+		/*
+		 * FIXME: Activation should happen immediately since this
+		 * function is just called after pipe is fully trained and
+		 * enabled.
+		 * However on some platforms we face issues when first
+		 * activation follows a modeset so quickly.
+		 *     - On VLV/CHV we get bank screen on first activation
+		 *     - On HSW/BDW we get a recoverable frozen screen until
+		 *       next exit-activate sequence.
+		 */
+		schedule_delayed_work(&dev_priv->psr.work,
+				      msecs_to_jiffies(intel_dp->panel_power_cycle_delay * 5));
+	}
+}
+
 /**
  * intel_psr_enable - Enable PSR
  * @intel_dp: Intel DP
@@ -647,27 +702,10 @@ void intel_psr_enable(struct intel_dp *intel_dp,
 	dev_priv->psr.psr2_support = crtc_state->has_psr2;
 	dev_priv->psr.busy_frontbuffer_bits = 0;
 
-	dev_priv->psr.setup_vsc(intel_dp, crtc_state);
-	dev_priv->psr.enable_sink(intel_dp);
-	dev_priv->psr.enable_source(intel_dp, crtc_state);
 	dev_priv->psr.enabled = intel_dp;
 
-	if (INTEL_GEN(dev_priv) >= 9) {
-		intel_psr_activate(intel_dp);
-	} else {
-		/*
-		 * FIXME: Activation should happen immediately since this
-		 * function is just called after pipe is fully trained and
-		 * enabled.
-		 * However on some platforms we face issues when first
-		 * activation follows a modeset so quickly.
-		 *     - On VLV/CHV we get bank screen on first activation
-		 *     - On HSW/BDW we get a recoverable frozen screen until
-		 *       next exit-activate sequence.
-		 */
-		schedule_delayed_work(&dev_priv->psr.work,
-				      msecs_to_jiffies(intel_dp->panel_power_cycle_delay * 5));
-	}
+	if (dev_priv->psr.global_enable)
+		__intel_psr_enable(dev_priv, intel_dp, crtc_state);
 
 unlock:
 	mutex_unlock(&dev_priv->psr.lock);
@@ -752,6 +790,16 @@ static void hsw_psr_disable(struct intel_dp *intel_dp,
 	psr_aux_io_power_put(intel_dp);
 }
 
+void __intel_psr_disable(struct drm_i915_private *dev_priv,
+			 struct intel_dp *intel_dp,
+			 const struct intel_crtc_state *old_crtc_state)
+{
+	dev_priv->psr.disable_source(intel_dp, old_crtc_state);
+
+	/* Disable PSR on Sink */
+	drm_dp_dpcd_writeb(&intel_dp->aux, DP_PSR_EN_CFG, 0);
+}
+
 /**
  * intel_psr_disable - Disable PSR
  * @intel_dp: Intel DP
@@ -773,15 +821,13 @@ void intel_psr_disable(struct intel_dp *intel_dp,
 		return;
 
 	mutex_lock(&dev_priv->psr.lock);
-	if (!dev_priv->psr.enabled) {
+	if (intel_dp != dev_priv->psr.enabled) {
 		mutex_unlock(&dev_priv->psr.lock);
 		return;
 	}
 
-	dev_priv->psr.disable_source(intel_dp, old_crtc_state);
-
-	/* Disable PSR on Sink */
-	drm_dp_dpcd_writeb(&intel_dp->aux, DP_PSR_EN_CFG, 0);
+	if (intel_psr_enabled(dev_priv))
+		__intel_psr_disable(dev_priv, intel_dp, old_crtc_state);
 
 	dev_priv->psr.enabled = NULL;
 	mutex_unlock(&dev_priv->psr.lock);
@@ -833,11 +879,11 @@ static void intel_psr_work(struct work_struct *work)
 		}
 	}
 	mutex_lock(&dev_priv->psr.lock);
-	intel_dp = dev_priv->psr.enabled;
-
-	if (!intel_dp)
+	if (!intel_psr_enabled(dev_priv))
 		goto unlock;
 
+	intel_dp = dev_priv->psr.enabled;
+
 	/*
 	 * The delayed work can race with an invalidate hence we need to
 	 * recheck. Since psr_flush first clears this and then reschedules we
@@ -933,7 +979,7 @@ void intel_psr_single_frame_update(struct drm_i915_private *dev_priv,
 		return;
 
 	mutex_lock(&dev_priv->psr.lock);
-	if (!dev_priv->psr.enabled) {
+	if (!intel_psr_enabled(dev_priv)) {
 		mutex_unlock(&dev_priv->psr.lock);
 		return;
 	}
@@ -979,7 +1025,7 @@ void intel_psr_invalidate(struct drm_i915_private *dev_priv,
 		return;
 
 	mutex_lock(&dev_priv->psr.lock);
-	if (!dev_priv->psr.enabled) {
+	if (!intel_psr_enabled(dev_priv)) {
 		mutex_unlock(&dev_priv->psr.lock);
 		return;
 	}
@@ -1022,7 +1068,7 @@ void intel_psr_flush(struct drm_i915_private *dev_priv,
 		return;
 
 	mutex_lock(&dev_priv->psr.lock);
-	if (!dev_priv->psr.enabled) {
+	if (!intel_psr_enabled(dev_priv)) {
 		mutex_unlock(&dev_priv->psr.lock);
 		return;
 	}
@@ -1081,26 +1127,9 @@ void intel_psr_init(struct drm_i915_private *dev_priv)
 	if (i915_modparams.enable_psr == -1)
 		i915_modparams.enable_psr = 0;
 
-	/* Set link_standby x link_off defaults */
-	if (IS_HASWELL(dev_priv) || IS_BROADWELL(dev_priv))
-		/* HSW and BDW require workarounds that we don't implement. */
-		dev_priv->psr.link_standby = false;
-	else if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))
-		/* On VLV and CHV only standby mode is supported. */
-		dev_priv->psr.link_standby = true;
-	else
-		/* For new platforms let's respect VBT back again */
-		dev_priv->psr.link_standby = dev_priv->vbt.psr.full_link;
+	dev_priv->psr.link_standby = intel_psr_default_link_standby(dev_priv);
 
-	/* Override link_standby x link_off defaults */
-	if (i915_modparams.enable_psr == 2 && !dev_priv->psr.link_standby) {
-		DRM_DEBUG_KMS("PSR: Forcing link standby\n");
-		dev_priv->psr.link_standby = true;
-	}
-	if (i915_modparams.enable_psr == 3 && dev_priv->psr.link_standby) {
-		DRM_DEBUG_KMS("PSR: Forcing main link off\n");
-		dev_priv->psr.link_standby = false;
-	}
+	dev_priv->psr.global_enable = i915_modparams.enable_psr;
 
 	INIT_DELAYED_WORK(&dev_priv->psr.work, intel_psr_work);
 	mutex_init(&dev_priv->psr.lock);
-- 
2.16.2



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