drm/i915: Read PSR caps/intermediate freqs/etc. only once on eDP

Currently we re-read a bunch of static eDP panel caps from the DPCD
over and over again. Let's do it only once to save some time and effort.

v2: Make thing less confusing with intel_edp_init_dpcd() (Chris)
    Move no_aux_handshake setup in there as well
v3: Move tps3/rate printout to intel_dp_long_pulse() so that
    we'll still get them on eDP as well

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> (v1)
Link: http://patchwork.freedesktop.org/patch/msgid/1469800359-7087-1-git-send-email-ville.syrjala@linux.intel.com

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 001f74f..0a9ade9 100644 (file)
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -3395,84 +3395,67 @@ intel_dp_link_down(struct intel_dp *intel_dp)
 }
 
 static bool
-intel_dp_get_dpcd(struct intel_dp *intel_dp)
+intel_dp_read_dpcd(struct intel_dp *intel_dp)
 {
-       struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
-       struct drm_device *dev = dig_port->base.base.dev;
-       struct drm_i915_private *dev_priv = to_i915(dev);
-
        if (drm_dp_dpcd_read(&intel_dp->aux, 0x000, intel_dp->dpcd,
                             sizeof(intel_dp->dpcd)) < 0)
                return false; /* aux transfer failed */
 
        DRM_DEBUG_KMS("DPCD: %*ph\n", (int) sizeof(intel_dp->dpcd), intel_dp->dpcd);
 
-       if (intel_dp->dpcd[DP_DPCD_REV] == 0)
-               return false; /* DPCD not present */
+       return intel_dp->dpcd[DP_DPCD_REV] != 0;
+}
 
-       if (drm_dp_dpcd_read(&intel_dp->aux, DP_SINK_COUNT,
-                            &intel_dp->sink_count, 1) < 0)
-               return false;
+static bool
+intel_edp_init_dpcd(struct intel_dp *intel_dp)
+{
+       struct drm_i915_private *dev_priv =
+               to_i915(dp_to_dig_port(intel_dp)->base.base.dev);
 
-       /*
-        * Sink count can change between short pulse hpd hence
-        * a member variable in intel_dp will track any changes
-        * between short pulse interrupts.
-        */
-       intel_dp->sink_count = DP_GET_SINK_COUNT(intel_dp->sink_count);
+       /* this function is meant to be called only once */
+       WARN_ON(intel_dp->dpcd[DP_DPCD_REV] != 0);
 
-       /*
-        * SINK_COUNT == 0 and DOWNSTREAM_PORT_PRESENT == 1 implies that
-        * a dongle is present but no display. Unless we require to know
-        * if a dongle is present or not, we don't need to update
-        * downstream port information. So, an early return here saves
-        * time from performing other operations which are not required.
-        */
-       if (!is_edp(intel_dp) && !intel_dp->sink_count)
+       if (!intel_dp_read_dpcd(intel_dp))
                return false;
 
-       /* Check if the panel supports PSR */
-       memset(intel_dp->psr_dpcd, 0, sizeof(intel_dp->psr_dpcd));
-       if (is_edp(intel_dp)) {
-               drm_dp_dpcd_read(&intel_dp->aux, DP_PSR_SUPPORT,
-                                intel_dp->psr_dpcd,
-                                sizeof(intel_dp->psr_dpcd));
-               if (intel_dp->psr_dpcd[0] & DP_PSR_IS_SUPPORTED) {
-                       dev_priv->psr.sink_support = true;
-                       DRM_DEBUG_KMS("Detected EDP PSR Panel.\n");
-               }
-
-               if (INTEL_INFO(dev)->gen >= 9 &&
-                       (intel_dp->psr_dpcd[0] & DP_PSR2_IS_SUPPORTED)) {
-                       uint8_t frame_sync_cap;
-
-                       dev_priv->psr.sink_support = true;
-                       drm_dp_dpcd_read(&intel_dp->aux,
-                                        DP_SINK_DEVICE_AUX_FRAME_SYNC_CAP,
-                                        &frame_sync_cap, 1);
-                       dev_priv->psr.aux_frame_sync = frame_sync_cap ? true : false;
-                       /* PSR2 needs frame sync as well */
-                       dev_priv->psr.psr2_support = dev_priv->psr.aux_frame_sync;
-                       DRM_DEBUG_KMS("PSR2 %s on sink",
-                               dev_priv->psr.psr2_support ? "supported" : "not supported");
-               }
-
-               /* Read the eDP Display control capabilities registers */
-               memset(intel_dp->edp_dpcd, 0, sizeof(intel_dp->edp_dpcd));
-               if ((intel_dp->dpcd[DP_EDP_CONFIGURATION_CAP] & DP_DPCD_DISPLAY_CONTROL_CAPABLE) &&
-                               (drm_dp_dpcd_read(&intel_dp->aux, DP_EDP_DPCD_REV,
-                                               intel_dp->edp_dpcd, sizeof(intel_dp->edp_dpcd)) ==
-                                                               sizeof(intel_dp->edp_dpcd)))
-                       DRM_DEBUG_KMS("EDP DPCD : %*ph\n", (int) sizeof(intel_dp->edp_dpcd),
-                                       intel_dp->edp_dpcd);
-       }
+       if (intel_dp->dpcd[DP_DPCD_REV] >= 0x11)
+               dev_priv->no_aux_handshake = intel_dp->dpcd[DP_MAX_DOWNSPREAD] &
+                       DP_NO_AUX_HANDSHAKE_LINK_TRAINING;
 
-       DRM_DEBUG_KMS("Display Port TPS3 support: source %s, sink %s\n",
-                     yesno(intel_dp_source_supports_hbr2(intel_dp)),
-                     yesno(drm_dp_tps3_supported(intel_dp->dpcd)));
+       /* Check if the panel supports PSR */
+       drm_dp_dpcd_read(&intel_dp->aux, DP_PSR_SUPPORT,
+                        intel_dp->psr_dpcd,
+                        sizeof(intel_dp->psr_dpcd));
+       if (intel_dp->psr_dpcd[0] & DP_PSR_IS_SUPPORTED) {
+               dev_priv->psr.sink_support = true;
+               DRM_DEBUG_KMS("Detected EDP PSR Panel.\n");
+       }
+
+       if (INTEL_GEN(dev_priv) >= 9 &&
+           (intel_dp->psr_dpcd[0] & DP_PSR2_IS_SUPPORTED)) {
+               uint8_t frame_sync_cap;
+
+               dev_priv->psr.sink_support = true;
+               drm_dp_dpcd_read(&intel_dp->aux,
+                                DP_SINK_DEVICE_AUX_FRAME_SYNC_CAP,
+                                &frame_sync_cap, 1);
+               dev_priv->psr.aux_frame_sync = frame_sync_cap ? true : false;
+               /* PSR2 needs frame sync as well */
+               dev_priv->psr.psr2_support = dev_priv->psr.aux_frame_sync;
+               DRM_DEBUG_KMS("PSR2 %s on sink",
+                             dev_priv->psr.psr2_support ? "supported" : "not supported");
+       }
+
+       /* Read the eDP Display control capabilities registers */
+       if ((intel_dp->dpcd[DP_EDP_CONFIGURATION_CAP] & DP_DPCD_DISPLAY_CONTROL_CAPABLE) &&
+           drm_dp_dpcd_read(&intel_dp->aux, DP_EDP_DPCD_REV,
+                            intel_dp->edp_dpcd, sizeof(intel_dp->edp_dpcd) ==
+                            sizeof(intel_dp->edp_dpcd)))
+               DRM_DEBUG_KMS("EDP DPCD : %*ph\n", (int) sizeof(intel_dp->edp_dpcd),
+                             intel_dp->edp_dpcd);
 
        /* Intermediate frequency support */
-       if (is_edp(intel_dp) && (intel_dp->edp_dpcd[0] >= 0x03)) { /* eDp v1.4 or higher */
+       if (intel_dp->edp_dpcd[0] >= 0x03) { /* eDp v1.4 or higher */
                __le16 sink_rates[DP_MAX_SUPPORTED_RATES];
                int i;
 
@@ -3491,7 +3474,36 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp)
                intel_dp->num_sink_rates = i;
        }
 
-       intel_dp_print_rates(intel_dp);
+       return true;
+}
+
+
+static bool
+intel_dp_get_dpcd(struct intel_dp *intel_dp)
+{
+       if (!intel_dp_read_dpcd(intel_dp))
+               return false;
+
+       if (drm_dp_dpcd_read(&intel_dp->aux, DP_SINK_COUNT,
+                            &intel_dp->sink_count, 1) < 0)
+               return false;
+
+       /*
+        * Sink count can change between short pulse hpd hence
+        * a member variable in intel_dp will track any changes
+        * between short pulse interrupts.
+        */
+       intel_dp->sink_count = DP_GET_SINK_COUNT(intel_dp->sink_count);
+
+       /*
+        * SINK_COUNT == 0 and DOWNSTREAM_PORT_PRESENT == 1 implies that
+        * a dongle is present but no display. Unless we require to know
+        * if a dongle is present or not, we don't need to update
+        * downstream port information. So, an early return here saves
+        * time from performing other operations which are not required.
+        */
+       if (!is_edp(intel_dp) && !intel_dp->sink_count)
+               return false;
 
        if (!(intel_dp->dpcd[DP_DOWNSTREAMPORT_PRESENT] &
              DP_DWN_STRM_PORT_PRESENT))
@@ -4252,6 +4264,12 @@ intel_dp_long_pulse(struct intel_connector *intel_connector)
        if (intel_encoder->type != INTEL_OUTPUT_EDP)
                intel_encoder->type = INTEL_OUTPUT_DP;
 
+       DRM_DEBUG_KMS("Display Port TPS3 support: source %s, sink %s\n",
+                     yesno(intel_dp_source_supports_hbr2(intel_dp)),
+                     yesno(drm_dp_tps3_supported(intel_dp->dpcd)));
+
+       intel_dp_print_rates(intel_dp);
+
        intel_dp_probe_oui(intel_dp);
 
        ret = intel_dp_probe_mst(intel_dp);
@@ -5413,14 +5431,9 @@ static bool intel_edp_init_connector(struct intel_dp *intel_dp,
        pps_unlock(intel_dp);
 
        /* Cache DPCD and EDID for edp. */
-       has_dpcd = intel_dp_get_dpcd(intel_dp);
+       has_dpcd = intel_edp_init_dpcd(intel_dp);
 
-       if (has_dpcd) {
-               if (intel_dp->dpcd[DP_DPCD_REV] >= 0x11)
-                       dev_priv->no_aux_handshake =
-                               intel_dp->dpcd[DP_MAX_DOWNSPREAD] &
-                               DP_NO_AUX_HANDSHAKE_LINK_TRAINING;
-       } else {
+       if (!has_dpcd) {
                /* if this fails, presume the device is a ghost */
                DRM_INFO("failed to retrieve link info, disabling eDP\n");
                goto out_vdd_off;