From 724d0351cd08eb93f3cd9021c3a26ce1f1c79f7f Mon Sep 17 00:00:00 2001 From: Sanjay Chitroda Date: Mon, 22 Jun 2026 11:00:00 +0530 Subject: [PATCH] iio: pressure: hid-sensor-press: Avoid race between callback setup and device exposure The driver currently exposes the IIO device to userspace before completing sensor hub callback registration, and similarly removes callbacks while the device can still be accessed during teardown. This creates a timing window where userspace may enable the buffer before callbacks are available. In such cases: - samples can be dropped, - buffered reads may observe stale or no data. Reorder probe and remove paths to ensure callbacks are active before device exposure and are removed after device is no longer accessible. This avoids a race window leading to data loss. Signed-off-by: Sanjay Chitroda Reviewed-by: Andy Shevchenko Acked-by: Srinivas Pandruvada Signed-off-by: Jonathan Cameron --- drivers/iio/pressure/hid-sensor-press.c | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-) diff --git a/drivers/iio/pressure/hid-sensor-press.c b/drivers/iio/pressure/hid-sensor-press.c index 3e47a10d72a8..8f81a6d65b9f 100644 --- a/drivers/iio/pressure/hid-sensor-press.c +++ b/drivers/iio/pressure/hid-sensor-press.c @@ -291,12 +291,6 @@ static int hid_press_probe(struct platform_device *pdev) return ret; } - ret = iio_device_register(indio_dev); - if (ret) { - dev_err(&pdev->dev, "device register failed\n"); - goto error_remove_trigger; - } - press_state->callbacks.send_event = press_proc_event; press_state->callbacks.capture_sample = press_capture_sample; press_state->callbacks.pdev = pdev; @@ -304,13 +298,19 @@ static int hid_press_probe(struct platform_device *pdev) &press_state->callbacks); if (ret < 0) { dev_err(&pdev->dev, "callback reg failed\n"); - goto error_iio_unreg; + goto error_remove_trigger; + } + + ret = iio_device_register(indio_dev); + if (ret) { + dev_err(&pdev->dev, "device register failed\n"); + goto error_remove_callback; } return ret; -error_iio_unreg: - iio_device_unregister(indio_dev); +error_remove_callback: + sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_PRESSURE); error_remove_trigger: hid_sensor_remove_trigger(indio_dev, &press_state->common_attributes); return ret; @@ -323,8 +323,8 @@ static void hid_press_remove(struct platform_device *pdev) struct iio_dev *indio_dev = platform_get_drvdata(pdev); struct press_state *press_state = iio_priv(indio_dev); - sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_PRESSURE); iio_device_unregister(indio_dev); + sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_PRESSURE); hid_sensor_remove_trigger(indio_dev, &press_state->common_attributes); }