Patch "remoteproc: sysmon: Wait for SSCTL service to come up" has been added to the 5.18-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    remoteproc: sysmon: Wait for SSCTL service to come up

to the 5.18-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     remoteproc-sysmon-wait-for-ssctl-service-to-come-up.patch
and it can be found in the queue-5.18 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 854db316a3d1e4ae37f0defe5bf9b2a22eeef107
Author: Sibi Sankar <quic_sibis@xxxxxxxxxxx>
Date:   Tue Jul 5 17:38:19 2022 +0530

    remoteproc: sysmon: Wait for SSCTL service to come up
    
    [ Upstream commit 47c04e00eff86a81cd357c3feed04c86089bcb85 ]
    
    The SSCTL service comes up after a finite time when the remote Q6 comes
    out of reset. Any graceful shutdowns requested during this period will
    be a NOP and abrupt tearing down of the glink channel might lead to pending
    transactions on the remote Q6 side and will ultimately lead to a fatal
    error. Fix this by waiting for the SSCTL service when a graceful shutdown
    is requested.
    
    Fixes: 1fb82ee806d1 ("remoteproc: qcom: Introduce sysmon")
    Reviewed-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx>
    Signed-off-by: Sibi Sankar <quic_sibis@xxxxxxxxxxx>
    Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
    Link: https://lore.kernel.org/r/1657022900-2049-7-git-send-email-quic_sibis@xxxxxxxxxxx
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/remoteproc/qcom_sysmon.c b/drivers/remoteproc/qcom_sysmon.c
index 9fca81492863..a9f04dd83ab6 100644
--- a/drivers/remoteproc/qcom_sysmon.c
+++ b/drivers/remoteproc/qcom_sysmon.c
@@ -41,6 +41,7 @@ struct qcom_sysmon {
 	struct completion comp;
 	struct completion ind_comp;
 	struct completion shutdown_comp;
+	struct completion ssctl_comp;
 	struct mutex lock;
 
 	bool ssr_ack;
@@ -445,6 +446,8 @@ static int ssctl_new_server(struct qmi_handle *qmi, struct qmi_service *svc)
 
 	svc->priv = sysmon;
 
+	complete(&sysmon->ssctl_comp);
+
 	return 0;
 }
 
@@ -501,6 +504,7 @@ static int sysmon_start(struct rproc_subdev *subdev)
 		.ssr_event = SSCTL_SSR_EVENT_AFTER_POWERUP
 	};
 
+	reinit_completion(&sysmon->ssctl_comp);
 	mutex_lock(&sysmon->state_lock);
 	sysmon->state = SSCTL_SSR_EVENT_AFTER_POWERUP;
 	blocking_notifier_call_chain(&sysmon_notifiers, 0, (void *)&event);
@@ -545,6 +549,11 @@ static void sysmon_stop(struct rproc_subdev *subdev, bool crashed)
 	if (crashed)
 		return;
 
+	if (sysmon->ssctl_instance) {
+		if (!wait_for_completion_timeout(&sysmon->ssctl_comp, HZ / 2))
+			dev_err(sysmon->dev, "timeout waiting for ssctl service\n");
+	}
+
 	if (sysmon->ssctl_version)
 		sysmon->shutdown_acked = ssctl_request_shutdown(sysmon);
 	else if (sysmon->ept)
@@ -631,6 +640,7 @@ struct qcom_sysmon *qcom_add_sysmon_subdev(struct rproc *rproc,
 	init_completion(&sysmon->comp);
 	init_completion(&sysmon->ind_comp);
 	init_completion(&sysmon->shutdown_comp);
+	init_completion(&sysmon->ssctl_comp);
 	mutex_init(&sysmon->lock);
 	mutex_init(&sysmon->state_lock);