drm/i915/icl: fix transcoder state readout

Commit 2ca711caeca2 ("drm/i915/icl: Consider DSI for getting transcoder
state") clobbers the previously read TRANS_DDI_FUNC_CTL_EDP register
contents with TRANS_DDI_FUNC_CTL_DSI0 contents. Fix the state readout,
and handle DSI 1 while at it.

Use a bitmask for iterating and logging transcoders, because the allowed
combinations are a bit funky.

Fixes: 2ca711caeca2 ("drm/i915/icl: Consider DSI for getting transcoder state")
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=108928
Cc: Ville Syrjala <ville.syrjala@linux.intel.com>
Cc: Madhav Chauhan <madhav.chauhan@intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181204101926.17174-1-jani.nikula@intel.com

1 files changed, 31 insertions, 21 deletions

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index a2584f977ab1..07c861884c70 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -9476,13 +9476,18 @@ static bool hsw_get_transcoder_state(struct intel_crtc *crtc,
         struct drm_device *dev = crtc->base.dev;
         struct drm_i915_private *dev_priv = to_i915(dev);
         enum intel_display_power_domain power_domain;
+        unsigned long panel_transcoder_mask = BIT(TRANSCODER_EDP);
+        unsigned long enabled_panel_transcoders = 0;
+        enum transcoder panel_transcoder;
         u32 tmp;
-        bool is_dsi = false;
-        bool is_edp = false;
+
+        if (IS_ICELAKE(dev_priv))
+                panel_transcoder_mask |=
+                        BIT(TRANSCODER_DSI_0) | BIT(TRANSCODER_DSI_1);
 
         /*
          * The pipe->transcoder mapping is fixed with the exception of the eDP
-         * transcoder handled below.
+         * and DSI transcoders handled below.
          */
         pipe_config->cpu_transcoder = (enum transcoder) crtc->pipe;
 
@@ -9490,23 +9495,26 @@ static bool hsw_get_transcoder_state(struct intel_crtc *crtc,
          * XXX: Do intel_display_power_get_if_enabled before reading this (for
          * consistency and less surprising code; it's in always on power).
          */
-        tmp = I915_READ(TRANS_DDI_FUNC_CTL(TRANSCODER_EDP));
-        if (tmp & TRANS_DDI_FUNC_ENABLE)
-                is_edp = true;
+        for_each_set_bit(panel_transcoder, &panel_transcoder_mask, 32) {
+                enum pipe trans_pipe;
 
-        if (IS_ICELAKE(dev_priv)) {
-                tmp = I915_READ(TRANS_DDI_FUNC_CTL(TRANSCODER_DSI_0));
-                if (tmp & TRANS_DDI_FUNC_ENABLE)
-                        is_dsi = true;
-        }
+                tmp = I915_READ(TRANS_DDI_FUNC_CTL(panel_transcoder));
+                if (!(tmp & TRANS_DDI_FUNC_ENABLE))
+                        continue;
 
-        WARN_ON(is_edp && is_dsi);
+                /*
+                 * Log all enabled ones, only use the first one.
+                 *
+                 * FIXME: This won't work for two separate DSI displays.
+                 */
+                enabled_panel_transcoders |= BIT(panel_transcoder);
+                if (enabled_panel_transcoders != BIT(panel_transcoder))
+                        continue;
 
-        if (is_edp || is_dsi) {
-                enum pipe trans_pipe;
                 switch (tmp & TRANS_DDI_EDP_INPUT_MASK) {
                 default:
-                        WARN(1, "unknown pipe linked to edp transcoder\n");
+                        WARN(1, "unknown pipe linked to transcoder %s\n",
+                             transcoder_name(panel_transcoder));
                         /* fall through */
                 case TRANS_DDI_EDP_INPUT_A_ONOFF:
                 case TRANS_DDI_EDP_INPUT_A_ON:
@@ -9520,14 +9528,16 @@ static bool hsw_get_transcoder_state(struct intel_crtc *crtc,
                         break;
                 }
 
-                if (trans_pipe == crtc->pipe) {
-                        if (is_edp)
-                                pipe_config->cpu_transcoder = TRANSCODER_EDP;
-                        else if (is_dsi)
-                                pipe_config->cpu_transcoder = TRANSCODER_DSI_0;
-                }
+                if (trans_pipe == crtc->pipe)
+                        pipe_config->cpu_transcoder = panel_transcoder;
         }
 
+        /*
+         * Valid combos: none, eDP, DSI0, DSI1, DSI0+DSI1
+         */
+        WARN_ON((enabled_panel_transcoders & BIT(TRANSCODER_EDP)) &&
+                enabled_panel_transcoders != BIT(TRANSCODER_EDP));
+
         power_domain = POWER_DOMAIN_TRANSCODER(pipe_config->cpu_transcoder);
         if (!intel_display_power_get_if_enabled(dev_priv, power_domain))
                 return false;