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From: Bjorn Andersson <bjorn.andersson@linaro.org>
To: Ohad Ben-Cohen <ohad@wizery.com>,
	Bjorn Andersson <bjorn.andersson@linaro.org>,
	Jeremy McNicoll <jmcnicol@redhat.com>,
	Will Newton <will.newton@gmail.com>
Cc: linux-remoteproc@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-arm-msm@vger.kernel.org, Chris Lew <clew@quicinc.com>
Subject: [PATCH 1/5] rpmsg: smd: Perform handshake during open
Date: Tue, 12 Dec 2017 15:58:53 -0800	[thread overview]
Message-ID: <20171212235857.10432-2-bjorn.andersson@linaro.org> (raw)
In-Reply-To: <20171212235857.10432-1-bjorn.andersson@linaro.org>

Validate the the remote side is opening the channel that we've found by
performing a handshake when opening the channel.

Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
---
 drivers/rpmsg/qcom_smd.c | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/drivers/rpmsg/qcom_smd.c b/drivers/rpmsg/qcom_smd.c
index b01774e9fac0..58dd44493420 100644
--- a/drivers/rpmsg/qcom_smd.c
+++ b/drivers/rpmsg/qcom_smd.c
@@ -200,6 +200,7 @@ struct qcom_smd_channel {
 	char *name;
 	enum smd_channel_state state;
 	enum smd_channel_state remote_state;
+	wait_queue_head_t state_change_event;
 
 	struct smd_channel_info_pair *info;
 	struct smd_channel_info_word_pair *info_word;
@@ -570,6 +571,8 @@ static bool qcom_smd_channel_intr(struct qcom_smd_channel *channel)
 	if (remote_state != channel->remote_state) {
 		channel->remote_state = remote_state;
 		need_state_scan = true;
+
+		wake_up_interruptible_all(&channel->state_change_event);
 	}
 	/* Indicate that we have seen any state change */
 	SET_RX_CHANNEL_FLAG(channel, fSTATE, 0);
@@ -786,7 +789,9 @@ static int __qcom_smd_send(struct qcom_smd_channel *channel, const void *data,
 static int qcom_smd_channel_open(struct qcom_smd_channel *channel,
 				 rpmsg_rx_cb_t cb)
 {
+	struct qcom_smd_edge *edge = channel->edge;
 	size_t bb_size;
+	int ret;
 
 	/*
 	 * Packets are maximum 4k, but reduce if the fifo is smaller
@@ -798,9 +803,33 @@ static int qcom_smd_channel_open(struct qcom_smd_channel *channel,
 
 	qcom_smd_channel_set_callback(channel, cb);
 	qcom_smd_channel_set_state(channel, SMD_CHANNEL_OPENING);
+
+	/* Wait for remote to enter opening or opened */
+	ret = wait_event_interruptible_timeout(channel->state_change_event,
+			channel->remote_state == SMD_CHANNEL_OPENING ||
+			channel->remote_state == SMD_CHANNEL_OPENED,
+			HZ);
+	if (!ret) {
+		dev_err(&edge->dev, "remote side did not enter opening state\n");
+		goto out_close_timeout;
+	}
+
 	qcom_smd_channel_set_state(channel, SMD_CHANNEL_OPENED);
 
+	/* Wait for remote to enter opened */
+	ret = wait_event_interruptible_timeout(channel->state_change_event,
+			channel->remote_state == SMD_CHANNEL_OPENED,
+			HZ);
+	if (!ret) {
+		dev_err(&edge->dev, "remote side did not enter open state\n");
+		goto out_close_timeout;
+	}
+
 	return 0;
+
+out_close_timeout:
+	qcom_smd_channel_set_state(channel, SMD_CHANNEL_CLOSED);
+	return -ETIMEDOUT;
 }
 
 /*
@@ -1055,6 +1084,7 @@ static struct qcom_smd_channel *qcom_smd_create_channel(struct qcom_smd_edge *ed
 	mutex_init(&channel->tx_lock);
 	spin_lock_init(&channel->recv_lock);
 	init_waitqueue_head(&channel->fblockread_event);
+	init_waitqueue_head(&channel->state_change_event);
 
 	info = qcom_smem_get(edge->remote_pid, smem_info_item, &info_size);
 	if (IS_ERR(info)) {
-- 
2.15.0

  reply	other threads:[~2017-12-12 23:59 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-12-12 23:58 [PATCH 0/5] Qualcomm SMD updates Bjorn Andersson
2017-12-12 23:58 ` Bjorn Andersson [this message]
2018-01-27  1:32   ` [PATCH 1/5] rpmsg: smd: Perform handshake during open Jeremy McNicoll
2017-12-12 23:58 ` [PATCH 2/5] rpmsg: smd: Create device for all channels Bjorn Andersson
2018-01-27  1:01   ` Jeremy McNicoll
2018-02-02 22:57     ` Bjorn Andersson
2017-12-12 23:58 ` [PATCH 3/5] rpmsg: smd: Wake up all waiters Bjorn Andersson
2017-12-12 23:58 ` [PATCH 4/5] rpmsg: smd: Fail send on a closed channel Bjorn Andersson
2017-12-12 23:58 ` [PATCH 5/5] rpmsg: smd: Don't hold the tx lock during wait Bjorn Andersson
2018-01-27  1:35 ` [PATCH 0/5] Qualcomm SMD updates Jeremy McNicoll

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