drm/i915: Pass down rc in intel_encoder->compute_config()

Something that I completely missed when implementing the new MST VCPI
atomic helpers is that with those helpers, there's technically a chance
of us having to grab additional modeset locks in ->compute_config() and
furthermore, that means we have the potential to hit a normal modeset
deadlock. However, because ->compute_config() only returns a bool this
means we can't return -EDEADLK when we need to drop locks and try again
which means we end up just failing the atomic check permanently. Whoops.

So, fix this by modifying ->compute_config() to pass down an actual
error code instead of a bool so that the atomic check can be restarted
on modeset deadlocks.

Thanks to Ville Syrjälä for pointing this out!

Changes since v1:
* Add some newlines
* Return only -EINVAL from hsw_crt_compute_config()
* Propogate return code from intel_dp_compute_dsc_params()
* Change all of the intel_dp_compute_link_config*() variants
* Don't miss if (hdmi_port_clock_valid()) branch in
  intel_hdmi_compute_config()

Signed-off-by: Lyude Paul <lyude@redhat.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Fixes: eceae1472467 ("drm/dp_mst: Start tracking per-port VCPI allocations")
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=109320
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190115200800.3121-1-lyude@redhat.com

1 files changed, 9 insertions, 9 deletions

diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index a3252064b8d2..19d9abd2666e 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -222,9 +222,9 @@ struct intel_encoder {
 	enum intel_output_type (*compute_output_type)(struct intel_encoder *,
 						      struct intel_crtc_state *,
 						      struct drm_connector_state *);
-	bool (*compute_config)(struct intel_encoder *,
-			       struct intel_crtc_state *,
-			       struct drm_connector_state *);
+	int (*compute_config)(struct intel_encoder *,
+			      struct intel_crtc_state *,
+			      struct drm_connector_state *);
 	void (*pre_pll_enable)(struct intel_encoder *,
 			       const struct intel_crtc_state *,
 			       const struct drm_connector_state *);
@@ -1806,9 +1806,9 @@ void intel_dp_sink_set_decompression_state(struct intel_dp *intel_dp,
 void intel_dp_encoder_reset(struct drm_encoder *encoder);
 void intel_dp_encoder_suspend(struct intel_encoder *intel_encoder);
 void intel_dp_encoder_destroy(struct drm_encoder *encoder);
-bool intel_dp_compute_config(struct intel_encoder *encoder,
-			     struct intel_crtc_state *pipe_config,
-			     struct drm_connector_state *conn_state);
+int intel_dp_compute_config(struct intel_encoder *encoder,
+			    struct intel_crtc_state *pipe_config,
+			    struct drm_connector_state *conn_state);
 bool intel_dp_is_edp(struct intel_dp *intel_dp);
 bool intel_dp_is_port_edp(struct drm_i915_private *dev_priv, enum port port);
 enum irqreturn intel_dp_hpd_pulse(struct intel_digital_port *intel_dig_port,
@@ -1966,9 +1966,9 @@ void intel_hdmi_init(struct drm_i915_private *dev_priv, i915_reg_t hdmi_reg,
 void intel_hdmi_init_connector(struct intel_digital_port *intel_dig_port,
 			       struct intel_connector *intel_connector);
 struct intel_hdmi *enc_to_intel_hdmi(struct drm_encoder *encoder);
-bool intel_hdmi_compute_config(struct intel_encoder *encoder,
-			       struct intel_crtc_state *pipe_config,
-			       struct drm_connector_state *conn_state);
+int intel_hdmi_compute_config(struct intel_encoder *encoder,
+			      struct intel_crtc_state *pipe_config,
+			      struct drm_connector_state *conn_state);
 bool intel_hdmi_handle_sink_scrambling(struct intel_encoder *encoder,
 				       struct drm_connector *connector,
 				       bool high_tmds_clock_ratio,