drm/i915/bdw: Add support for DRRS to switch RR
For Broadwell, there is one instance of Transcoder MN values per transcoder.
For dynamic switching between multiple refreshr rates, M/N values may be
reprogrammed on the fly. Link N programming triggers update of all data and
link M & N registers and the new M/N values will be used in the next frame
that is output.
V2: [By Ram]: intel_dp_set_m_n() is rewritten to accommodate
gen >= 8 [Rodrigo]
V3: Coding style correction [Ram]
V4: [By Ram] intel_dp_set_m_n modifications are moved into a
separate patch, retaining only DRRS related changes here [Rodrigo]
Signed-off-by: Vandana Kannan <vandana.kannan@intel.com>
Signed-off-by: Pradeep Bhat <pradeep.bhat@intel.com>
Signed-off-by: Ramalingam C <ramalingam.c@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@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 dfd94c5..c837ded 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -4808,12 +4808,24 @@
return;
}
- if (INTEL_INFO(dev)->gen > 6 && INTEL_INFO(dev)->gen < 8) {
+ if (INTEL_INFO(dev)->gen >= 8) {
+ switch (index) {
+ case DRRS_HIGH_RR:
+ intel_dp_set_m_n(intel_crtc, M1_N1);
+ break;
+ case DRRS_LOW_RR:
+ intel_dp_set_m_n(intel_crtc, M2_N2);
+ break;
+ case DRRS_MAX_RR:
+ default:
+ DRM_ERROR("Unsupported refreshrate type\n");
+ }
+ } else if (INTEL_INFO(dev)->gen > 6) {
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_m_n(intel_crtc);
} else {
val &= ~PIPECONF_EDP_RR_MODE_SWITCH;
}