[PATCH] power: supply: twl4030_charger: cancel workers via devm

bci is devm-allocated. Two workers (bci->work and bci->current_worker)
dereference it. twl4030_bci_remove() disables charging and masks
interrupts. It cancels neither worker. A worker pending at remove() can
run after devm frees bci.

The USB transceiver comes from devm_usb_get_phy_by_node(). devm
unregisters its notifier only after remove() returns. A cancel_work_sync()
in remove() can then race a notifier reschedule. devm_work_autocancel()
and devm_delayed_work_autocancel() avoid that. They cancel the workers
during devm release, before bci is freed.

Suggested-by: Sebastian Reichel <[email protected]>
Fixes: d6ccc442b1210 ("twl4030_charger: Make the driver atomic notifier safe")
Cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Maoyi Xie <[email protected]>
---
 drivers/power/supply/twl4030_charger.c | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/drivers/power/supply/twl4030_charger.c b/drivers/power/supply/twl4030_charger.c
index 04216b2bfb6c3..d8bae2daac23d 100644
--- a/drivers/power/supply/twl4030_charger.c
+++ b/drivers/power/supply/twl4030_charger.c
@@ -14,6 +14,7 @@
 #include <linux/err.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>
+#include <linux/devm-helpers.h>
 #include <linux/interrupt.h>
 #include <linux/mfd/twl.h>
 #include <linux/power_supply.h>
@@ -1002,8 +1003,18 @@ static int twl4030_bci_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, bci);
 
-	INIT_WORK(&bci->work, twl4030_bci_usb_work);
-	INIT_DELAYED_WORK(&bci->current_worker, twl4030_current_worker);
+	/* Register current_worker first: devm cancels in reverse order, and
+	 * bci->work can reschedule current_worker.
+	 */
+	ret = devm_delayed_work_autocancel(&pdev->dev, &bci->current_worker,
+					   twl4030_current_worker);
+	if (ret)
+		return ret;
+
+	ret = devm_work_autocancel(&pdev->dev, &bci->work,
+				   twl4030_bci_usb_work);
+	if (ret)
+		return ret;
 
 	bci->channel_vac = devm_iio_channel_get(&pdev->dev, "vac");
 	if (IS_ERR(bci->channel_vac)) {
-- 
2.34.1