drm/i915: Add reverse mapping between port and intel_encoder

This patch adds a reverse mapping from a digital port number to
intel_encoder object containing the corresponding intel_digital_port.
It simplifies the query of the encoder a lot.

Note that, even if it's a valid digital port, the dig_port_map[] might
point still to NULL -- usually it implies a DP MST port.  Due to this
fact, the NULL check in each place has no WARN_ON() and just skips the
port.  Once when the situation changes in future, we might introduce
WARN_ON() for a more strict check.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 1 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index e1ceff7..e1456ea 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -6003,6 +6003,7 @@ intel_dp_init(struct drm_device *dev,
 	}
 
 	intel_dig_port->port = port;
+	dev_priv->dig_port_map[port] = intel_encoder;
 	intel_dig_port->dp.output_reg = output_reg;
 
 	intel_encoder->type = INTEL_OUTPUT_DISPLAYPORT;