[PATCH 2/3] drm/bridge: it6505: Setup links in it6505_irq_hpd

Pin-yen Lin treapking at chromium.org
Wed Oct 12 16:28:58 UTC 2022


Move the DPCD read and link setup steps to HPD IRQ handler to remove
an unnecessary dependency between .detect callback and the HPD IRQ
handler before registering it6505 as a DRM bridge. This is safe because
there is always a .detect call after each HPD IRQ handler triggered by
the drm_helper_hpd_irq_event call.

Signed-off-by: Pin-yen Lin <treapking at chromium.org>
---

 drivers/gpu/drm/bridge/ite-it6505.c | 74 +++++++++++------------------
 1 file changed, 29 insertions(+), 45 deletions(-)

diff --git a/drivers/gpu/drm/bridge/ite-it6505.c b/drivers/gpu/drm/bridge/ite-it6505.c
index f7f6c3e20fae..cf94e44ec73a 100644
--- a/drivers/gpu/drm/bridge/ite-it6505.c
+++ b/drivers/gpu/drm/bridge/ite-it6505.c
@@ -725,28 +725,6 @@ static void it6505_calc_video_info(struct it6505 *it6505)
 			     DRM_MODE_ARG(&it6505->video_info));
 }
 
-static int it6505_drm_dp_link_probe(struct drm_dp_aux *aux,
-				    struct it6505_drm_dp_link *link)
-{
-	u8 values[3];
-	int err;
-
-	memset(link, 0, sizeof(*link));
-
-	err = drm_dp_dpcd_read(aux, DP_DPCD_REV, values, sizeof(values));
-	if (err < 0)
-		return err;
-
-	link->revision = values[0];
-	link->rate = drm_dp_bw_code_to_link_rate(values[1]);
-	link->num_lanes = values[2] & DP_MAX_LANE_COUNT_MASK;
-
-	if (values[2] & DP_ENHANCED_FRAME_CAP)
-		link->capabilities = DP_ENHANCED_FRAME_CAP;
-
-	return 0;
-}
-
 static int it6505_drm_dp_link_set_power(struct drm_dp_aux *aux,
 					struct it6505_drm_dp_link *link,
 					u8 mode)
@@ -1456,11 +1434,19 @@ static void it6505_parse_link_capabilities(struct it6505 *it6505)
 	int bcaps;
 
 	if (it6505->dpcd[0] == 0) {
-		it6505_aux_on(it6505);
-		it6505_get_dpcd(it6505, DP_DPCD_REV, it6505->dpcd,
-				ARRAY_SIZE(it6505->dpcd));
+		dev_err(dev, "DPCD is not initialized");
+		return;
 	}
 
+	memset(link, 0, sizeof(*link));
+
+	link->revision = it6505->dpcd[0];
+	link->rate = drm_dp_bw_code_to_link_rate(it6505->dpcd[1]);
+	link->num_lanes = it6505->dpcd[2] & DP_MAX_LANE_COUNT_MASK;
+
+	if (it6505->dpcd[2] & DP_ENHANCED_FRAME_CAP)
+		link->capabilities = DP_ENHANCED_FRAME_CAP;
+
 	DRM_DEV_DEBUG_DRIVER(dev, "DPCD Rev.: %d.%d",
 			     link->revision >> 4, link->revision & 0x0F);
 
@@ -2328,14 +2314,21 @@ static void it6505_irq_hpd(struct it6505 *it6505)
 	DRM_DEV_DEBUG_DRIVER(dev, "hpd change interrupt, change to %s",
 			     it6505->hpd_state ? "high" : "low");
 
-	if (it6505->bridge.dev)
-		drm_helper_hpd_irq_event(it6505->bridge.dev);
-	DRM_DEV_DEBUG_DRIVER(dev, "it6505->sink_count: %d",
-			     it6505->sink_count);
-
 	if (it6505->hpd_state) {
 		wait_for_completion_timeout(&it6505->wait_edid_complete,
 					    msecs_to_jiffies(6000));
+		it6505_aux_on(it6505);
+		if (it6505->dpcd[0] == 0) {
+			it6505_get_dpcd(it6505, DP_DPCD_REV, it6505->dpcd,
+					ARRAY_SIZE(it6505->dpcd));
+			it6505_variable_config(it6505);
+			it6505_parse_link_capabilities(it6505);
+		}
+		it6505->auto_train_retry = AUTO_TRAIN_RETRY;
+
+		DRM_DEV_DEBUG_DRIVER(dev, "it6505->sink_count: %d",
+				     it6505->sink_count);
+
 		it6505_lane_termination_on(it6505);
 		it6505_lane_power_on(it6505);
 
@@ -2363,6 +2356,9 @@ static void it6505_irq_hpd(struct it6505 *it6505)
 		it6505_lane_off(it6505);
 		it6505_link_reset_step_train(it6505);
 	}
+
+	if (it6505->bridge.dev)
+		drm_helper_hpd_irq_event(it6505->bridge.dev);
 }
 
 static void it6505_irq_hpd_irq(struct it6505 *it6505)
@@ -2625,26 +2621,14 @@ static enum drm_connector_status it6505_detect(struct it6505 *it6505)
 		goto unlock;
 
 	if (it6505->enable_drv_hold) {
-		status = it6505_get_sink_hpd_status(it6505) ?
-					connector_status_connected :
-					connector_status_disconnected;
+		status = it6505->hpd_state ?  connector_status_connected :
+					      connector_status_disconnected;
 		goto unlock;
 	}
 
-	if (it6505_get_sink_hpd_status(it6505)) {
-		it6505_aux_on(it6505);
-		it6505_drm_dp_link_probe(&it6505->aux, &it6505->link);
+	if (it6505->hpd_state) {
 		it6505_drm_dp_link_set_power(&it6505->aux, &it6505->link,
 					     DP_SET_POWER_D0);
-		it6505->auto_train_retry = AUTO_TRAIN_RETRY;
-
-		if (it6505->dpcd[0] == 0) {
-			it6505_get_dpcd(it6505, DP_DPCD_REV, it6505->dpcd,
-					ARRAY_SIZE(it6505->dpcd));
-			it6505_variable_config(it6505);
-			it6505_parse_link_capabilities(it6505);
-		}
-
 		dp_sink_count = it6505_dpcd_read(it6505, DP_SINK_COUNT);
 		it6505->sink_count = DP_GET_SINK_COUNT(dp_sink_count);
 		DRM_DEV_DEBUG_DRIVER(dev, "it6505->sink_count:%d branch:%d",
-- 
2.38.0.rc1.362.ged0d419d3c-goog



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