From 079876e90bb8b2e2fcddaaad32658729566e4da9 Mon Sep 17 00:00:00 2001
From: Kiran Gunda <kgunda@codeaurora.org>
Date: Mon, 14 Sep 2020 13:04:55 +0530
Subject: [PATCH] power: supply: qti_battery_charger: Handle probe failure
 gracefully

Due to a race condition between the probe and glink message
callback, it is observed that the glink messages/notifications
can be handled even after the probe failure which leads to
an invalid memory access. Fix it by introducing "initialized"
flag. While at it, add few error logs to identify the exact
message failures.

Change-Id: I18e61dea734efde6a11ee072793da8eead269b12
Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
---
 drivers/power/supply/qti_battery_charger.c | 30 ++++++++++++++++++----
 1 file changed, 25 insertions(+), 5 deletions(-)

diff --git a/drivers/power/supply/qti_battery_charger.c b/drivers/power/supply/qti_battery_charger.c
index 9ee0e431bbff..e999a2496dbd 100644
--- a/drivers/power/supply/qti_battery_charger.c
+++ b/drivers/power/supply/qti_battery_charger.c
@@ -240,6 +240,8 @@ struct battery_chg_dev {
 	u32				last_fcc_ua;
 	u32				usb_icl_ua;
 	bool				restrict_chg_en;
+	/* To track the driver initialization status */
+	bool				initialized;
 };
 
 static const int battery_prop_map[BATT_PROP_MAX] = {
@@ -725,6 +727,12 @@ static int battery_chg_callback(void *priv, void *data, size_t len)
 	pr_debug("owner: %u type: %u opcode: %#x len: %zu\n", hdr->owner,
 		hdr->type, hdr->opcode, len);
 
+	if (!bcdev->initialized) {
+		pr_debug("Driver initialization failed: Dropping glink callback message: state %d\n",
+			 bcdev->state);
+		return 0;
+	}
+
 	if (hdr->opcode == BC_NOTIFY_IND)
 		handle_notification(bcdev, data, len);
 	else
@@ -816,8 +824,10 @@ static int usb_psy_set_icl(struct battery_chg_dev *bcdev, u32 prop_id, int val)
 	int rc;
 
 	rc = read_property_id(bcdev, pst, USB_ADAP_TYPE);
-	if (rc < 0)
+	if (rc < 0) {
+		pr_err("Failed to read prop USB_ADAP_TYPE, rc=%d\n", rc);
 		return rc;
+	}
 
 	/* Allow this only for SDP or USB_PD and not for other charger types */
 	if (pst->prop[USB_ADAP_TYPE] != POWER_SUPPLY_USB_TYPE_SDP &&
@@ -836,7 +846,9 @@ static int usb_psy_set_icl(struct battery_chg_dev *bcdev, u32 prop_id, int val)
 		temp = UINT_MAX;
 
 	rc = write_property_id(bcdev, pst, prop_id, temp);
-	if (!rc) {
+	if (rc < 0) {
+		pr_err("Failed to set ICL (%u uA) rc=%d\n", temp, rc);
+	} else {
 		pr_debug("Set ICL to %u\n", temp);
 		bcdev->usb_icl_ua = temp;
 	}
@@ -1756,8 +1768,11 @@ static int battery_chg_parse_dt(struct battery_chg_dev *bcdev)
 	len = rc;
 
 	rc = read_property_id(bcdev, pst, BATT_CHG_CTRL_LIM_MAX);
-	if (rc < 0)
+	if (rc < 0) {
+		pr_err("Failed to read prop BATT_CHG_CTRL_LIM_MAX, rc=%d\n",
+			rc);
 		return rc;
+	}
 
 	prev = pst->prop[BATT_CHG_CTRL_LIM_MAX];
 
@@ -1888,13 +1903,16 @@ static int battery_chg_probe(struct platform_device *pdev)
 		return rc;
 	}
 
+	bcdev->initialized = true;
 	bcdev->reboot_notifier.notifier_call = battery_chg_ship_mode;
 	bcdev->reboot_notifier.priority = 255;
 	register_reboot_notifier(&bcdev->reboot_notifier);
 
 	rc = battery_chg_parse_dt(bcdev);
-	if (rc < 0)
+	if (rc < 0) {
+		dev_err(dev, "Failed to parse dt rc=%d\n", rc);
 		goto error;
+	}
 
 	bcdev->restrict_fcc_ua = DEFAULT_RESTRICT_FCC_UA;
 	platform_set_drvdata(pdev, bcdev);
@@ -1907,7 +1925,7 @@ static int battery_chg_probe(struct platform_device *pdev)
 	bcdev->battery_class.class_groups = battery_class_groups;
 	rc = class_register(&bcdev->battery_class);
 	if (rc < 0) {
-		pr_err("Failed to create battery_class rc=%d\n", rc);
+		dev_err(dev, "Failed to create battery_class rc=%d\n", rc);
 		goto error;
 	}
 
@@ -1917,6 +1935,8 @@ static int battery_chg_probe(struct platform_device *pdev)
 
 	return 0;
 error:
+	bcdev->initialized = false;
+	complete(&bcdev->ack);
 	pmic_glink_unregister_client(bcdev->client);
 	unregister_reboot_notifier(&bcdev->reboot_notifier);
 	return rc;