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()

[Cherry-picked from drm-misc-next to drm-intel-next-queued to fix
 linux-next & drm-tip conflict, while waiting for proper propagation of
 the DP MST series that this commit fixes. In hindsight, a topic branch
 might have been a better approach for it.]

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
(cherry picked from commit 96550555a78ca3c9fda4b358549a5622810fe32c)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Daniel Vetter <daniel@ffwll.ch>

1 files changed, 7 insertions, 7 deletions

diff --git a/drivers/gpu/drm/i915/intel_sdvo.c b/drivers/gpu/drm/i915/intel_sdvo.c
index b08fed11219f..ba58b06f730d 100644
--- a/drivers/gpu/drm/i915/intel_sdvo.c
+++ b/drivers/gpu/drm/i915/intel_sdvo.c
@@ -1107,9 +1107,9 @@ static void i9xx_adjust_sdvo_tv_clock(struct intel_crtc_state *pipe_config)
 	pipe_config->clock_set = true;
 }
 
-static bool intel_sdvo_compute_config(struct intel_encoder *encoder,
-				      struct intel_crtc_state *pipe_config,
-				      struct drm_connector_state *conn_state)
+static int intel_sdvo_compute_config(struct intel_encoder *encoder,
+				     struct intel_crtc_state *pipe_config,
+				     struct drm_connector_state *conn_state)
 {
 	struct intel_sdvo *intel_sdvo = to_sdvo(encoder);
 	struct intel_sdvo_connector_state *intel_sdvo_state =
@@ -1134,7 +1134,7 @@ static bool intel_sdvo_compute_config(struct intel_encoder *encoder,
 	 */
 	if (IS_TV(intel_sdvo_connector)) {
 		if (!intel_sdvo_set_output_timings_from_mode(intel_sdvo, mode))
-			return false;
+			return -EINVAL;
 
 		(void) intel_sdvo_get_preferred_input_mode(intel_sdvo,
 							   intel_sdvo_connector,
@@ -1144,7 +1144,7 @@ static bool intel_sdvo_compute_config(struct intel_encoder *encoder,
 	} else if (IS_LVDS(intel_sdvo_connector)) {
 		if (!intel_sdvo_set_output_timings_from_mode(intel_sdvo,
 							     intel_sdvo_connector->base.panel.fixed_mode))
-			return false;
+			return -EINVAL;
 
 		(void) intel_sdvo_get_preferred_input_mode(intel_sdvo,
 							   intel_sdvo_connector,
@@ -1153,7 +1153,7 @@ static bool intel_sdvo_compute_config(struct intel_encoder *encoder,
 	}
 
 	if (adjusted_mode->flags & DRM_MODE_FLAG_DBLSCAN)
-		return false;
+		return -EINVAL;
 
 	/*
 	 * Make the CRTC code factor in the SDVO pixel multiplier.  The
@@ -1193,7 +1193,7 @@ static bool intel_sdvo_compute_config(struct intel_encoder *encoder,
 	if (intel_sdvo_connector->is_hdmi)
 		adjusted_mode->picture_aspect_ratio = conn_state->picture_aspect_ratio;
 
-	return true;
+	return 0;
 }
 
 #define UPDATE_PROPERTY(input, NAME) \