drm/i915: Add support for DRRS to switch RR
This patch computes and stored 2nd M/N/TU for switching to different
refresh rate dynamically. PIPECONF_EDP_RR_MODE_SWITCH bit helps toggle
between alternate refresh rates programmed in 2nd M/N/TU registers.
v2: Daniel's review comments
Computing M2/N2 in compute_config and storing it in crtc_config
v3: Modified reference to edp_downclock and edp_downclock_avail based on the
changes made to move them from dev_private to intel_panel.
v4: Modified references to is_drrs_supported based on the changes made to
rename it to drrs_support.
v5: Jani's review comments
Removed superfluous return statements. Changed support for Gen 7 and above.
Corrected indentation. Re-structured the code which finds crtc and connector
from encoder. Changed some logs to be less verbose.
v6: Modifying i915_drrs to include only intel connector as intel_dp can be
derived from intel connector when required.
v7: As per internal review comments, acquiring mutex just before accessing
drrs RR. As per Chris's review comments, added documentation about the use
of locking in the function.
v8: Incorporated Jani's review comments.
Removed reference to edp_downclock.
v9: Jani's review comments. Modified comment in set_drrs. Changed index to
type edp_drrs_refresh_rate_type. Check if PSR is enabled before setting
registers fo DRRS.
Signed-off-by: Pradeep Bhat <pradeep.bhat@intel.com>
Signed-off-by: Vandana Kannan <vandana.kannan@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 517a8cc..b50b170 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -737,6 +737,20 @@
}
}
+static void
+intel_dp_set_m2_n2(struct intel_crtc *crtc, struct intel_link_m_n *m_n)
+{
+ struct drm_device *dev = crtc->base.dev;
+ struct drm_i915_private *dev_priv = dev->dev_private;
+ enum transcoder transcoder = crtc->config.cpu_transcoder;
+
+ I915_WRITE(PIPE_DATA_M2(transcoder),
+ TU_SIZE(m_n->tu) | m_n->gmch_m);
+ I915_WRITE(PIPE_DATA_N2(transcoder), m_n->gmch_n);
+ I915_WRITE(PIPE_LINK_M2(transcoder), m_n->link_m);
+ I915_WRITE(PIPE_LINK_N2(transcoder), m_n->link_n);
+}
+
bool
intel_dp_compute_config(struct intel_encoder *encoder,
struct intel_crtc_config *pipe_config)
@@ -841,6 +855,14 @@
pipe_config->port_clock,
&pipe_config->dp_m_n);
+ if (intel_connector->panel.downclock_mode != NULL &&
+ intel_dp->drrs_state.type == SEAMLESS_DRRS_SUPPORT) {
+ intel_link_compute_m_n(bpp, lane_count,
+ intel_connector->panel.downclock_mode->clock,
+ pipe_config->port_clock,
+ &pipe_config->dp_m2_n2);
+ }
+
intel_dp_set_clock(encoder, pipe_config, intel_dp->link_bw);
return true;
@@ -3632,6 +3654,90 @@
I915_READ(pp_div_reg));
}
+void intel_dp_set_drrs_state(struct drm_device *dev, int refresh_rate)
+{
+ struct drm_i915_private *dev_priv = dev->dev_private;
+ struct intel_encoder *encoder;
+ struct intel_dp *intel_dp = NULL;
+ struct intel_crtc_config *config = NULL;
+ struct intel_crtc *intel_crtc = NULL;
+ struct intel_connector *intel_connector = dev_priv->drrs.connector;
+ u32 reg, val;
+ enum edp_drrs_refresh_rate_type index = DRRS_HIGH_RR;
+
+ if (refresh_rate <= 0) {
+ DRM_DEBUG_KMS("Refresh rate should be positive non-zero.\n");
+ return;
+ }
+
+ if (intel_connector == NULL) {
+ DRM_DEBUG_KMS("DRRS supported for eDP only.\n");
+ return;
+ }
+
+ if (INTEL_INFO(dev)->gen < 8 && intel_edp_is_psr_enabled(dev)) {
+ DRM_DEBUG_KMS("DRRS is disabled as PSR is enabled\n");
+ return;
+ }
+
+ encoder = intel_attached_encoder(&intel_connector->base);
+ intel_dp = enc_to_intel_dp(&encoder->base);
+ intel_crtc = encoder->new_crtc;
+
+ if (!intel_crtc) {
+ DRM_DEBUG_KMS("DRRS: intel_crtc not initialized\n");
+ return;
+ }
+
+ config = &intel_crtc->config;
+
+ if (intel_dp->drrs_state.type < SEAMLESS_DRRS_SUPPORT) {
+ DRM_DEBUG_KMS("Only Seamless DRRS supported.\n");
+ return;
+ }
+
+ if (intel_connector->panel.downclock_mode->vrefresh == refresh_rate)
+ index = DRRS_LOW_RR;
+
+ if (index == intel_dp->drrs_state.refresh_rate_type) {
+ DRM_DEBUG_KMS(
+ "DRRS requested for previously set RR...ignoring\n");
+ return;
+ }
+
+ if (!intel_crtc->active) {
+ DRM_DEBUG_KMS("eDP encoder disabled. CRTC not Active\n");
+ return;
+ }
+
+ if (INTEL_INFO(dev)->gen > 6 && INTEL_INFO(dev)->gen < 8) {
+ reg = PIPECONF(intel_crtc->config.cpu_transcoder);
+ val = I915_READ(reg);
+ if (index > DRRS_HIGH_RR) {
+ val |= PIPECONF_EDP_RR_MODE_SWITCH;
+ intel_dp_set_m2_n2(intel_crtc, &config->dp_m2_n2);
+ } else {
+ val &= ~PIPECONF_EDP_RR_MODE_SWITCH;
+ }
+ I915_WRITE(reg, val);
+ }
+
+ /*
+ * mutex taken to ensure that there is no race between differnt
+ * drrs calls trying to update refresh rate. This scenario may occur
+ * in future when idleness detection based DRRS in kernel and
+ * possible calls from user space to set differnt RR are made.
+ */
+
+ mutex_lock(&intel_dp->drrs_state.mutex);
+
+ intel_dp->drrs_state.refresh_rate_type = index;
+
+ mutex_unlock(&intel_dp->drrs_state.mutex);
+
+ DRM_DEBUG_KMS("eDP Refresh Rate set to : %dHz\n", refresh_rate);
+}
+
static struct drm_display_mode *
intel_dp_drrs_init(struct intel_digital_port *intel_dig_port,
struct intel_connector *intel_connector,
@@ -3661,6 +3767,10 @@
return NULL;
}
+ dev_priv->drrs.connector = intel_connector;
+
+ mutex_init(&intel_dp->drrs_state.mutex);
+
intel_dp->drrs_state.type = dev_priv->vbt.drrs_type;
intel_dp->drrs_state.refresh_rate_type = DRRS_HIGH_RR;