net: qrtr: mhi: synchronize qrtr and mhi preparation

Commit Message

Chris Lew Nov. 5, 2024, 1:29 a.m. UTC

From: Bhaumik Bhatt <[e-mail]>

The call to qrtr_endpoint_register() was moved before
mhi_prepare_for_transfer_autoqueue() to prevent a case where a dl
callback can occur before the qrtr endpoint is registered.

Now the reverse can happen where qrtr will try to send a packet
before the channels are prepared. Add a wait in the sending path to
ensure the channels are prepared before trying to do a ul transfer.

Fixes: 68a838b84eff ("net: qrtr: start MHI channel after endpoit creation")
Reported-by: Johan Hovold <[e-mail]>
Closes: https://lore.kernel.org/linux-arm-msm/[e-mail]/
Signed-off-by: Bhaumik Bhatt <[e-mail]>
Signed-off-by: Chris Lew <[e-mail]>
---
 net/qrtr/mhi.c | 7 +++++++
 1 file changed, 7 insertions(+)


---
base-commit: 1ffec08567f426a1c593e038cadc61bdc38cb467
change-id: 20241104-qrtr_mhi-dfec353030af

Best regards,

Patch

diff --git a/net/qrtr/mhi.c b/net/qrtr/mhi.c
index 69f53625a049..5b7268868bbd 100644
--- a/net/qrtr/mhi.c
+++ b/net/qrtr/mhi.c
@@ -15,6 +15,7 @@  struct qrtr_mhi_dev {
 	struct qrtr_endpoint ep;
 	struct mhi_device *mhi_dev;
 	struct device *dev;
+	struct completion prepared;
 };
 
 /* From MHI to QRTR */
@@ -53,6 +54,10 @@  static int qcom_mhi_qrtr_send(struct qrtr_endpoint *ep, struct sk_buff *skb)
 	if (skb->sk)
 		sock_hold(skb->sk);
 
+	rc = wait_for_completion_interruptible(&qdev->prepared);
+	if (rc)
+		goto free_skb;
+
 	rc = skb_linearize(skb);
 	if (rc)
 		goto free_skb;
@@ -85,6 +90,7 @@  static int qcom_mhi_qrtr_probe(struct mhi_device *mhi_dev,
 	qdev->mhi_dev = mhi_dev;
 	qdev->dev = &mhi_dev->dev;
 	qdev->ep.xmit = qcom_mhi_qrtr_send;
+	init_completion(&qdev->prepared);
 
 	dev_set_drvdata(&mhi_dev->dev, qdev);
 	rc = qrtr_endpoint_register(&qdev->ep, QRTR_EP_NID_AUTO);
@@ -97,6 +103,7 @@  static int qcom_mhi_qrtr_probe(struct mhi_device *mhi_dev,
 		qrtr_endpoint_unregister(&qdev->ep);
 		return rc;
 	}
+	complete_all(&qdev->prepared);
 
 	dev_dbg(qdev->dev, "Qualcomm MHI QRTR driver probed\n");