drm/i915/edp: fix eDP MSO pipe sanity checks for ADL-P

ADL-P supports stream splitter on pipe B in addition to pipe A. Update
the sanity check in intel_ddi_mso_get_config() to reflect this, and
remove the check in intel_ddi_mso_configure() as redundant with
encoder->pipe_mask. Abstract the splitter pipe mask to a single point of
truth while at it to avoid similar mistakes in the future.

Fixes: 7bc188cc2c8c ("drm/i915/adl_p: enable MSO on pipe B")
Cc: Uma Shankar <uma.shankar@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Swati Sharma <swati2.sharma@intel.com>
Reviewed-by: Swati Sharma <swati2.sharma@intel.com>
Tested-by: Swati Sharma <swati2.sharma@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210812132354.10885-1-jani.nikula@intel.com
(cherry picked from commit f6864b27d6d324771d979694de7ca455afbad32a)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
index be716b5..00dade4 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_ddi.c
+++ b/drivers/gpu/drm/i915/display/intel_ddi.c
@@ -2463,6 +2463,15 @@ static void intel_ddi_power_up_lanes(struct intel_encoder *encoder,
        }
 }
 
+/* Splitter enable for eDP MSO is limited to certain pipes. */
+static u8 intel_ddi_splitter_pipe_mask(struct drm_i915_private *i915)
+{
+       if (IS_ALDERLAKE_P(i915))
+               return BIT(PIPE_A) | BIT(PIPE_B);
+       else
+               return BIT(PIPE_A);
+}
+
 static void intel_ddi_mso_get_config(struct intel_encoder *encoder,
                                     struct intel_crtc_state *pipe_config)
 {
@@ -2480,8 +2489,7 @@ static void intel_ddi_mso_get_config(struct intel_encoder *encoder,
        if (!pipe_config->splitter.enable)
                return;
 
-       /* Splitter enable is supported for pipe A only. */
-       if (drm_WARN_ON(&i915->drm, pipe != PIPE_A)) {
+       if (drm_WARN_ON(&i915->drm, !(intel_ddi_splitter_pipe_mask(i915) & BIT(pipe)))) {
                pipe_config->splitter.enable = false;
                return;
        }
@@ -2513,10 +2521,6 @@ static void intel_ddi_mso_configure(const struct intel_crtc_state *crtc_state)
                return;
 
        if (crtc_state->splitter.enable) {
-               /* Splitter enable is supported for pipe A only. */
-               if (drm_WARN_ON(&i915->drm, pipe != PIPE_A))
-                       return;
-
                dss1 |= SPLITTER_ENABLE;
                dss1 |= OVERLAP_PIXELS(crtc_state->splitter.pixel_overlap);
                if (crtc_state->splitter.link_count == 2)
@@ -4743,12 +4747,8 @@ void intel_ddi_init(struct drm_i915_private *dev_priv, enum port port)
 
                dig_port->hpd_pulse = intel_dp_hpd_pulse;
 
-               /* Splitter enable for eDP MSO is limited to certain pipes. */
-               if (dig_port->dp.mso_link_count) {
-                       encoder->pipe_mask = BIT(PIPE_A);
-                       if (IS_ALDERLAKE_P(dev_priv))
-                               encoder->pipe_mask |= BIT(PIPE_B);
-               }
+               if (dig_port->dp.mso_link_count)
+                       encoder->pipe_mask = intel_ddi_splitter_pipe_mask(dev_priv);
        }
 
        /* In theory we don't need the encoder->type check, but leave it just in