diff mbox series

soc: qcom: pmic_glink: Make client-lock non-sleeping

Message ID 20240430-pmic-glink-sleep-while-atomic-v1-1-88fb493e8545@quicinc.com
State Accepted
Commit 9329933699b32d467a99befa20415c4b2172389a
Headers show
Series soc: qcom: pmic_glink: Make client-lock non-sleeping | expand

Commit Message

Bjorn Andersson May 1, 2024, 3:38 a.m. UTC 
From: Bjorn Andersson <quic_bjorande@quicinc.com>

The recently introduced commit '635ce0db8956 ("soc: qcom: pmic_glink:
don't traverse clients list without a lock")' ensured that the clients
list is not modified while traversed.

But the callback is made from the GLINK IRQ handler and as such this
mutual exclusion can not be provided by a (sleepable) mutex.

Replace the mutex with a spinlock.

Fixes: 635ce0db8956 ("soc: qcom: pmic_glink: don't traverse clients list without a lock")
Signed-off-by: Bjorn Andersson <quic_bjorande@quicinc.com>
---
 drivers/soc/qcom/pmic_glink.c | 25 +++++++++++++++----------
 1 file changed, 15 insertions(+), 10 deletions(-)


---
base-commit: bb7a2467e6beef44a80a17d45ebf2931e7631083
change-id: 20240430-pmic-glink-sleep-while-atomic-d43c42c5add0

Best regards,
diff mbox series

Patch

diff --git a/drivers/soc/qcom/pmic_glink.c b/drivers/soc/qcom/pmic_glink.c
index 9bdbd8944c4e..40fb09d69014 100644
--- a/drivers/soc/qcom/pmic_glink.c
+++ b/drivers/soc/qcom/pmic_glink.c
@@ -11,6 +11,7 @@ 
 #include <linux/slab.h>
 #include <linux/soc/qcom/pdr.h>
 #include <linux/soc/qcom/pmic_glink.h>
+#include <linux/spinlock.h>
 
 enum {
 	PMIC_GLINK_CLIENT_BATT = 0,
@@ -36,7 +37,7 @@  struct pmic_glink {
 	unsigned int pdr_state;
 
 	/* serializing clients list updates */
-	struct mutex client_lock;
+	spinlock_t client_lock;
 	struct list_head clients;
 };
 
@@ -58,10 +59,11 @@  static void _devm_pmic_glink_release_client(struct device *dev, void *res)
 {
 	struct pmic_glink_client *client = (struct pmic_glink_client *)res;
 	struct pmic_glink *pg = client->pg;
+	unsigned long flags;
 
-	mutex_lock(&pg->client_lock);
+	spin_lock_irqsave(&pg->client_lock, flags);
 	list_del(&client->node);
-	mutex_unlock(&pg->client_lock);
+	spin_unlock_irqrestore(&pg->client_lock, flags);
 }
 
 struct pmic_glink_client *devm_pmic_glink_register_client(struct device *dev,
@@ -72,6 +74,7 @@  struct pmic_glink_client *devm_pmic_glink_register_client(struct device *dev,
 {
 	struct pmic_glink_client *client;
 	struct pmic_glink *pg = dev_get_drvdata(dev->parent);
+	unsigned long flags;
 
 	client = devres_alloc(_devm_pmic_glink_release_client, sizeof(*client), GFP_KERNEL);
 	if (!client)
@@ -84,12 +87,12 @@  struct pmic_glink_client *devm_pmic_glink_register_client(struct device *dev,
 	client->priv = priv;
 
 	mutex_lock(&pg->state_lock);
-	mutex_lock(&pg->client_lock);
+	spin_lock_irqsave(&pg->client_lock, flags);
 
 	list_add(&client->node, &pg->clients);
 	client->pdr_notify(client->priv, pg->client_state);
 
-	mutex_unlock(&pg->client_lock);
+	spin_unlock_irqrestore(&pg->client_lock, flags);
 	mutex_unlock(&pg->state_lock);
 
 	devres_add(dev, client);
@@ -112,6 +115,7 @@  static int pmic_glink_rpmsg_callback(struct rpmsg_device *rpdev, void *data,
 	struct pmic_glink_client *client;
 	struct pmic_glink_hdr *hdr;
 	struct pmic_glink *pg = dev_get_drvdata(&rpdev->dev);
+	unsigned long flags;
 
 	if (len < sizeof(*hdr)) {
 		dev_warn(pg->dev, "ignoring truncated message\n");
@@ -120,12 +124,12 @@  static int pmic_glink_rpmsg_callback(struct rpmsg_device *rpdev, void *data,
 
 	hdr = data;
 
-	mutex_lock(&pg->client_lock);
+	spin_lock_irqsave(&pg->client_lock, flags);
 	list_for_each_entry(client, &pg->clients, node) {
 		if (client->id == le32_to_cpu(hdr->owner))
 			client->cb(data, len, client->priv);
 	}
-	mutex_unlock(&pg->client_lock);
+	spin_unlock_irqrestore(&pg->client_lock, flags);
 
 	return 0;
 }
@@ -165,6 +169,7 @@  static void pmic_glink_state_notify_clients(struct pmic_glink *pg)
 {
 	struct pmic_glink_client *client;
 	unsigned int new_state = pg->client_state;
+	unsigned long flags;
 
 	if (pg->client_state != SERVREG_SERVICE_STATE_UP) {
 		if (pg->pdr_state == SERVREG_SERVICE_STATE_UP && pg->ept)
@@ -175,10 +180,10 @@  static void pmic_glink_state_notify_clients(struct pmic_glink *pg)
 	}
 
 	if (new_state != pg->client_state) {
-		mutex_lock(&pg->client_lock);
+		spin_lock_irqsave(&pg->client_lock, flags);
 		list_for_each_entry(client, &pg->clients, node)
 			client->pdr_notify(client->priv, new_state);
-		mutex_unlock(&pg->client_lock);
+		spin_unlock_irqrestore(&pg->client_lock, flags);
 		pg->client_state = new_state;
 	}
 }
@@ -265,7 +270,7 @@  static int pmic_glink_probe(struct platform_device *pdev)
 	pg->dev = &pdev->dev;
 
 	INIT_LIST_HEAD(&pg->clients);
-	mutex_init(&pg->client_lock);
+	spin_lock_init(&pg->client_lock);
 	mutex_init(&pg->state_lock);
 
 	match_data = (unsigned long *)of_device_get_match_data(&pdev->dev);