drm/i915: Unbreak check_digital_port_conflicts()

Atomic changes broke check_digital_port_conflicts(). It needs to look
at the global situation instead of just trying to find a conflict
within the current atomic state.

This bug made my HSW explode spectacularly after I had split the DDI
encoders into separate DP and HDMI encoders. With the fix, things
seem much more solid.

I hope holding the connection_mutex is enough protection that we can
actually walk the connectors even if they're not part of the current
atomic state...

v2: Regenerate the patch so that it actually applies (Jani)

Cc: stable@vger.kernel.org
Cc: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Fixes: 5448a00d3f06 ("drm/i915: Don't use staged config in check_digital_port_conflicts()")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1449764551-12466-1-git-send-email-ville.syrjala@linux.intel.com
(cherry picked from commit 0bff4858653312a10c83709e0009c3adb87e6f1e)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

1 files changed, 8 insertions, 4 deletions

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index beb0374a19f1..32cf97346978 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -12123,18 +12123,22 @@ static void intel_dump_pipe_config(struct intel_crtc *crtc,
 static bool check_digital_port_conflicts(struct drm_atomic_state *state)
 {
         struct drm_device *dev = state->dev;
-        struct intel_encoder *encoder;
         struct drm_connector *connector;
-        struct drm_connector_state *connector_state;
         unsigned int used_ports = 0;
-        int i;
 
         /*
          * Walk the connector list instead of the encoder
          * list to detect the problem on ddi platforms
          * where there's just one encoder per digital port.
          */
-        for_each_connector_in_state(state, connector, connector_state, i) {
+        drm_for_each_connector(connector, dev) {
+                struct drm_connector_state *connector_state;
+                struct intel_encoder *encoder;
+
+                connector_state = drm_atomic_get_existing_connector_state(state, connector);
+                if (!connector_state)
+                        connector_state = connector->state;
+
                 if (!connector_state->best_encoder)
                         continue;