[PATCH 3/3] drm/dp_mst: Remove single tx msg restriction.

[Sean Paul]

From: Sean Paul <seanpaul at chromium.org>

Now that we can support multiple simultaneous replies, remove the
restrictions placed on sending new tx msgs.

This patch essentially just reverts commit
  5a64967a2f3b ("drm/dp_mst: Have DP_Tx send one msg at a time")
now that the problem is solved in a different way.

Cc: Wayne Lin <Wayne.Lin at amd.com>
Signed-off-by: Sean Paul <seanpaul at chromium.org>
---
 drivers/gpu/drm/drm_dp_mst_topology.c | 14 ++------------
 include/drm/drm_dp_mst_helper.h       |  6 ------
 2 files changed, 2 insertions(+), 18 deletions(-)

diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index 7e6a82efdfc02..cbf0bb0ddeb84 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -1203,8 +1203,6 @@ static int drm_dp_mst_wait_tx_reply(struct drm_dp_mst_branch *mstb,
 		    txmsg->state == DRM_DP_SIDEBAND_TX_SENT) {
 			mstb->tx_slots[txmsg->seqno] = NULL;
 		}
-		mgr->is_waiting_for_dwn_reply = false;
-
 	}
 out:
 	if (unlikely(ret == -EIO) && drm_debug_enabled(DRM_UT_DP)) {
@@ -1214,7 +1212,6 @@ static int drm_dp_mst_wait_tx_reply(struct drm_dp_mst_branch *mstb,
 	}
 	mutex_unlock(&mgr->qlock);
 
-	drm_dp_mst_kick_tx(mgr);
 	return ret;
 }
 
@@ -2797,11 +2794,9 @@ static void process_single_down_tx_qlock(struct drm_dp_mst_topology_mgr *mgr)
 	ret = process_single_tx_qlock(mgr, txmsg, false);
 	if (ret == 1) {
 		/* txmsg is sent it should be in the slots now */
-		mgr->is_waiting_for_dwn_reply = true;
 		list_del(&txmsg->next);
 	} else if (ret) {
 		DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
-		mgr->is_waiting_for_dwn_reply = false;
 		list_del(&txmsg->next);
 		if (txmsg->seqno != -1)
 			txmsg->dst->tx_slots[txmsg->seqno] = NULL;
@@ -2841,8 +2836,7 @@ static void drm_dp_queue_down_tx(struct drm_dp_mst_topology_mgr *mgr,
 		drm_dp_mst_dump_sideband_msg_tx(&p, txmsg);
 	}
 
-	if (list_is_singular(&mgr->tx_msg_downq) &&
-	    !mgr->is_waiting_for_dwn_reply)
+	if (list_is_singular(&mgr->tx_msg_downq))
 		process_single_down_tx_qlock(mgr);
 	mutex_unlock(&mgr->qlock);
 }
@@ -3822,7 +3816,6 @@ static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr)
 	mutex_lock(&mgr->qlock);
 	txmsg->state = DRM_DP_SIDEBAND_TX_RX;
 	mstb->tx_slots[seqno] = NULL;
-	mgr->is_waiting_for_dwn_reply = false;
 	mutex_unlock(&mgr->qlock);
 
 	wake_up_all(&mgr->tx_waitq);
@@ -3830,9 +3823,6 @@ static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr)
 	return 0;
 
 out_clear_reply:
-	mutex_lock(&mgr->qlock);
-	mgr->is_waiting_for_dwn_reply = false;
-	mutex_unlock(&mgr->qlock);
 	if (msg)
 		memset(msg, 0, sizeof(struct drm_dp_sideband_msg_rx));
 out:
@@ -4670,7 +4660,7 @@ static void drm_dp_tx_work(struct work_struct *work)
 	struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, tx_work);
 
 	mutex_lock(&mgr->qlock);
-	if (!list_empty(&mgr->tx_msg_downq) && !mgr->is_waiting_for_dwn_reply)
+	if (!list_empty(&mgr->tx_msg_downq))
 		process_single_down_tx_qlock(mgr);
 	mutex_unlock(&mgr->qlock);
 }
diff --git a/include/drm/drm_dp_mst_helper.h b/include/drm/drm_dp_mst_helper.h
index 7d0341f94ce1b..fcc30e64c8e7e 100644
--- a/include/drm/drm_dp_mst_helper.h
+++ b/include/drm/drm_dp_mst_helper.h
@@ -619,12 +619,6 @@ struct drm_dp_mst_topology_mgr {
 	 * &drm_dp_sideband_msg_tx.state once they are queued
 	 */
 	struct mutex qlock;
-
-	/**
-	 * @is_waiting_for_dwn_reply: indicate whether is waiting for down reply
-	 */
-	bool is_waiting_for_dwn_reply;
-
 	/**
 	 * @tx_msg_downq: List of pending down replies.
 	 */
-- 
Sean Paul, Software Engineer, Google / Chromium OS