drm/i915: Fix fastset vs. pfit on/off on HSW EDP transcoder

On HSW the pipe A panel fitter lives inside the display power well,
and the input MUX for the EDP transcoder needs to be configured
appropriately to route the data through the power well as needed.
Changing the MUX setting is not allowed while the pipe is active,
so we need to force a full modeset whenever we need to change it.

Currently we may end up doing a fastset which won't change the
MUX settings, but it will drop the power well reference, and that
kills the pipe.

Cc: stable@vger.kernel.org
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Fixes: d19f958db23c ("drm/i915: Enable fastset for non-boot modesets.")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190425162906.5242-1-ville.syrjala@linux.intel.com
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
(cherry picked from commit 13b7648b7eab7e8259a2fb267b498bd9eba81ca0)
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

2 files changed, 19 insertions, 3 deletions

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 3bd40a4a6739..5098228f1302 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -12082,6 +12082,7 @@ intel_pipe_config_compare(struct drm_i915_private *dev_priv,
                           struct intel_crtc_state *pipe_config,
                           bool adjust)
 {
+        struct intel_crtc *crtc = to_intel_crtc(current_config->base.crtc);
         bool ret = true;
         bool fixup_inherited = adjust &&
                 (current_config->base.mode.private_flags & I915_MODE_FLAG_INHERITED) &&
@@ -12303,6 +12304,14 @@ intel_pipe_config_compare(struct drm_i915_private *dev_priv,
                 PIPE_CONF_CHECK_X(gmch_pfit.pgm_ratios);
         PIPE_CONF_CHECK_X(gmch_pfit.lvds_border_bits);
 
+        /*
+         * Changing the EDP transcoder input mux
+         * (A_ONOFF vs. A_ON) requires a full modeset.
+         */
+        if (IS_HASWELL(dev_priv) && crtc->pipe == PIPE_A &&
+            current_config->cpu_transcoder == TRANSCODER_EDP)
+                PIPE_CONF_CHECK_BOOL(pch_pfit.enabled);
+
         if (!adjust) {
                 PIPE_CONF_CHECK_I(pipe_src_w);
                 PIPE_CONF_CHECK_I(pipe_src_h);
diff --git a/drivers/gpu/drm/i915/intel_pipe_crc.c b/drivers/gpu/drm/i915/intel_pipe_crc.c
index e94b5b1bc1b7..e7c7be4911c1 100644
--- a/drivers/gpu/drm/i915/intel_pipe_crc.c
+++ b/drivers/gpu/drm/i915/intel_pipe_crc.c
@@ -311,10 +311,17 @@ retry:
         pipe_config->base.mode_changed = pipe_config->has_psr;
         pipe_config->crc_enabled = enable;
 
-        if (IS_HASWELL(dev_priv) && crtc->pipe == PIPE_A) {
+        if (IS_HASWELL(dev_priv) &&
+            pipe_config->base.active && crtc->pipe == PIPE_A &&
+            pipe_config->cpu_transcoder == TRANSCODER_EDP) {
+                bool old_need_power_well = pipe_config->pch_pfit.enabled ||
+                        pipe_config->pch_pfit.force_thru;
+                bool new_need_power_well = pipe_config->pch_pfit.enabled ||
+                        enable;
+
                 pipe_config->pch_pfit.force_thru = enable;
-                if (pipe_config->cpu_transcoder == TRANSCODER_EDP &&
-                    pipe_config->pch_pfit.enabled != enable)
+
+                if (old_need_power_well != new_need_power_well)
                         pipe_config->base.connectors_changed = true;
         }