[PATCH 1/2] rpmsg: glink: Transition intent request signaling to wait queue

From: Bjorn Andersson
Date: Mon Mar 27 2023 - 10:46:44 EST


Transition the intent request acknowledgement to use a wait queue so
that it's possible, in the next commit, to extend the wait to also wait
for an incoming intent.

Signed-off-by: Bjorn Andersson <quic_bjorande@xxxxxxxxxxx>
---
drivers/rpmsg/qcom_glink_native.c | 21 ++++++++++++---------
1 file changed, 12 insertions(+), 9 deletions(-)

diff --git a/drivers/rpmsg/qcom_glink_native.c b/drivers/rpmsg/qcom_glink_native.c
index 082cf7f4888e..e3494de7dce8 100644
--- a/drivers/rpmsg/qcom_glink_native.c
+++ b/drivers/rpmsg/qcom_glink_native.c
@@ -16,6 +16,7 @@
#include <linux/rpmsg.h>
#include <linux/sizes.h>
#include <linux/slab.h>
+#include <linux/wait.h>
#include <linux/workqueue.h>
#include <linux/mailbox_client.h>

@@ -145,7 +146,7 @@ enum {
* @open_req: completed once open-request has been received
* @intent_req_lock: Synchronises multiple intent requests
* @intent_req_result: Result of intent request
- * @intent_req_comp: Completion for intent_req signalling
+ * @intent_req_wq: wait queue for intent_req signalling
*/
struct glink_channel {
struct rpmsg_endpoint ept;
@@ -175,8 +176,8 @@ struct glink_channel {
struct completion open_req;

struct mutex intent_req_lock;
- bool intent_req_result;
- struct completion intent_req_comp;
+ int intent_req_result;
+ wait_queue_head_t intent_req_wq;
};

#define to_glink_channel(_ept) container_of(_ept, struct glink_channel, ept)
@@ -221,7 +222,7 @@ static struct glink_channel *qcom_glink_alloc_channel(struct qcom_glink *glink,

init_completion(&channel->open_req);
init_completion(&channel->open_ack);
- init_completion(&channel->intent_req_comp);
+ init_waitqueue_head(&channel->intent_req_wq);

INIT_LIST_HEAD(&channel->done_intents);
INIT_WORK(&channel->intent_work, qcom_glink_rx_done_work);
@@ -420,13 +421,13 @@ static void qcom_glink_handle_intent_req_ack(struct qcom_glink *glink,
}

channel->intent_req_result = granted;
- complete(&channel->intent_req_comp);
+ wake_up_all(&channel->intent_req_wq);
}

static void qcom_glink_intent_req_abort(struct glink_channel *channel)
{
channel->intent_req_result = 0;
- complete(&channel->intent_req_comp);
+ wake_up_all(&channel->intent_req_wq);
}

/**
@@ -1271,7 +1272,7 @@ static int qcom_glink_request_intent(struct qcom_glink *glink,

mutex_lock(&channel->intent_req_lock);

- reinit_completion(&channel->intent_req_comp);
+ WRITE_ONCE(channel->intent_req_result, -1);

cmd.id = GLINK_CMD_RX_INTENT_REQ;
cmd.cid = channel->lcid;
@@ -1281,12 +1282,14 @@ static int qcom_glink_request_intent(struct qcom_glink *glink,
if (ret)
goto unlock;

- ret = wait_for_completion_timeout(&channel->intent_req_comp, 10 * HZ);
+ ret = wait_event_timeout(channel->intent_req_wq,
+ READ_ONCE(channel->intent_req_result) >= 0,
+ 10 * HZ);
if (!ret) {
dev_err(glink->dev, "intent request timed out\n");
ret = -ETIMEDOUT;
} else {
- ret = channel->intent_req_result ? 0 : -ECANCELED;
+ ret = READ_ONCE(channel->intent_req_result) ? 0 : -ECANCELED;
}

unlock:
--
2.25.1