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Commit a8951570 authored by Arun Kumar Neelakantam's avatar Arun Kumar Neelakantam
Browse files

soc: qcom: glink_probe: Defer SSR unregister 



Calling SSR unregister for other peripherals from glink_ssr device remove
call back results in deadlock if multiple SSRs happens in parallel.

SSR unregister is defer to other worker to avoid notifier SRCU deadlock.

Change-Id: Ifa5c461201eec4b4beb8bf405bd0a2904a2cc90f
Signed-off-by: default avatarArun Kumar Neelakantam <aneela@codeaurora.org>
parent 8f765160

drivers/soc/qcom/glink_probe.c

+28 −9
Original line number Diff line number Diff line 
/* Copyright (c) 2017-2018, The Linux Foundation. All rights reserved.

/* Copyright (c) 2017-2019, The Linux Foundation. All rights reserved.

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 and
@@ -77,6 +77,7 @@ struct glink_ssr { 


	u32 seq_num;

	struct completion completion;

	struct work_struct unreg_work;

};



struct edge_info {
@@ -94,6 +95,20 @@ struct edge_info { 
};

LIST_HEAD(edge_infos);



static void glink_ssr_ssr_unreg_work(struct work_struct *work)

{

	struct glink_ssr *ssr = container_of(work, struct glink_ssr,

					     unreg_work);

	struct glink_ssr_nb *nb, *tmp;



	list_for_each_entry_safe(nb, tmp, &ssr->notify_list, list) {

		subsys_notif_unregister_notifier(nb->ssr_register_handle,

						 &nb->nb);

		kfree(nb);

	}

	kfree(ssr);

}



static int glink_ssr_ssr_cb(struct notifier_block *this,

			    unsigned long code, void *data)

{
@@ -103,6 +118,9 @@ static int glink_ssr_ssr_cb(struct notifier_block *this, 
	struct do_cleanup_msg msg;

	int ret;



	if (!dev || !ssr->ept)

		return NOTIFY_DONE;



	if (code == SUBSYS_AFTER_SHUTDOWN) {

		ssr->seq_num++;

		reinit_completion(&ssr->completion);
@@ -179,7 +197,7 @@ static void glink_ssr_init_notify(struct glink_ssr *ssr) 
		if (!node)

			break;



		nb = devm_kzalloc(dev, sizeof(*nb), GFP_KERNEL);

		nb = kzalloc(sizeof(*nb), GFP_KERNEL);

		if (!nb)

			return;
@@ -192,6 +210,7 @@ static void glink_ssr_init_notify(struct glink_ssr *ssr) 
		if (ret < 0) {

			GLINK_ERR(dev, "no qcom,glink-label for %s\n",

				  nb->ssr_label);

			kfree(nb);

			continue;

		}
@@ -202,6 +221,7 @@ static void glink_ssr_init_notify(struct glink_ssr *ssr) 
		if (IS_ERR_OR_NULL(handle)) {

			GLINK_ERR(dev, "register fail for %s SSR notifier\n",

				  nb->ssr_label);

			kfree(nb);

			continue;

		}
@@ -215,12 +235,13 @@ static int glink_ssr_probe(struct rpmsg_device *rpdev) 
{

	struct glink_ssr *ssr;



	ssr = devm_kzalloc(&rpdev->dev, sizeof(*ssr), GFP_KERNEL);

	ssr = kzalloc(sizeof(*ssr), GFP_KERNEL);

	if (!ssr)

		return -ENOMEM;



	INIT_LIST_HEAD(&ssr->notify_list);

	init_completion(&ssr->completion);

	INIT_WORK(&ssr->unreg_work, glink_ssr_ssr_unreg_work);



	ssr->dev = &rpdev->dev;

	ssr->ept = rpdev->ept;
@@ -235,14 +256,12 @@ static int glink_ssr_probe(struct rpmsg_device *rpdev) 
static void glink_ssr_remove(struct rpmsg_device *rpdev)

{

	struct glink_ssr *ssr = dev_get_drvdata(&rpdev->dev);

	struct glink_ssr_nb *nb;



	list_for_each_entry(nb, &ssr->notify_list, list) {

		subsys_notif_unregister_notifier(nb->ssr_register_handle,

						 &nb->nb);

	}



	ssr->dev = NULL;

	ssr->ept = NULL;

	dev_set_drvdata(&rpdev->dev, NULL);



	schedule_work(&ssr->unreg_work);

}



static const struct rpmsg_device_id glink_ssr_match[] = {