[PATCH V2 1/3] Revert "staging: vchiq_arm: Improve initial VCHIQ connect"

[Stefan Wahren]

The commit 3e5def4249b9 ("staging: vchiq_arm: Improve initial VCHIQ connect")
based on the assumption that in good case the VCHIQ connect always happen and
therefore the keep-alive thread is guaranteed to be woken up. This is wrong,
because in certain configurations there are no VCHIQ users and so the VCHIQ
connect never happen. So revert it.

Fixes: 3e5def4249b9 ("staging: vchiq_arm: Improve initial VCHIQ connect")
Reported-by: Maíra Canal <mcanal at igalia.com>
Closes: https://lore.kernel.org/linux-staging/ba35b960-a981-4671-9f7f-060da10feaa1@usp.br/
Cc: <stable at kernel.org>
Signed-off-by: Stefan Wahren <wahrenst at gmx.net>
Reviewed-by: Maíra Canal <mcanal at igalia.com>
---
 .../interface/vchiq_arm/vchiq_arm.c           | 28 ++++++++++++++-----
 .../interface/vchiq_arm/vchiq_core.c          |  1 -
 .../interface/vchiq_arm/vchiq_core.h          |  2 --
 3 files changed, 21 insertions(+), 10 deletions(-)

diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
index 5dbf8d53db09..cdf5687ad4f0 100644
--- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
+++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
@@ -97,6 +97,13 @@ struct vchiq_arm_state {
 	 * tracked separately with the state.
 	 */
 	int peer_use_count;
+
+	/*
+	 * Flag to indicate that the first vchiq connect has made it through.
+	 * This means that both sides should be fully ready, and we should
+	 * be able to suspend after this point.
+	 */
+	int first_connect;
 };
 
 static int
@@ -1329,19 +1336,26 @@ vchiq_check_service(struct vchiq_service *service)
 	return ret;
 }
 
-void vchiq_platform_connected(struct vchiq_state *state)
-{
-	struct vchiq_arm_state *arm_state = vchiq_platform_get_arm_state(state);
-
-	wake_up_process(arm_state->ka_thread);
-}
-
 void vchiq_platform_conn_state_changed(struct vchiq_state *state,
 				       enum vchiq_connstate oldstate,
 				       enum vchiq_connstate newstate)
 {
+	struct vchiq_arm_state *arm_state = vchiq_platform_get_arm_state(state);
+
 	dev_dbg(state->dev, "suspend: %d: %s->%s\n",
 		state->id, get_conn_state_name(oldstate), get_conn_state_name(newstate));
+	if (state->conn_state != VCHIQ_CONNSTATE_CONNECTED)
+		return;
+
+	write_lock_bh(&arm_state->susp_res_lock);
+	if (arm_state->first_connect) {
+		write_unlock_bh(&arm_state->susp_res_lock);
+		return;
+	}
+
+	arm_state->first_connect = 1;
+	write_unlock_bh(&arm_state->susp_res_lock);
+	wake_up_process(arm_state->ka_thread);
 }
 
 static const struct of_device_id vchiq_of_match[] = {
diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c
index e7b0c800a205..e2cac0898b8f 100644
--- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c
+++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c
@@ -3343,7 +3343,6 @@ vchiq_connect_internal(struct vchiq_state *state, struct vchiq_instance *instanc
 			return -EAGAIN;
 
 		vchiq_set_conn_state(state, VCHIQ_CONNSTATE_CONNECTED);
-		vchiq_platform_connected(state);
 		complete(&state->connect);
 	}
 
diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.h b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.h
index 3b5c0618e567..9b4e766990a4 100644
--- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.h
+++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.h
@@ -575,8 +575,6 @@ int vchiq_send_remote_use(struct vchiq_state *state);
 
 int vchiq_send_remote_use_active(struct vchiq_state *state);
 
-void vchiq_platform_connected(struct vchiq_state *state);
-
 void vchiq_platform_conn_state_changed(struct vchiq_state *state,
 				       enum vchiq_connstate oldstate,
 				  enum vchiq_connstate newstate);
-- 
2.34.1