diff options
| author | Joshua Crofts <joshua.crofts1@gmail.com> | 2026-05-13 16:35:52 +0200 |
|---|---|---|
| committer | Jonathan Cameron <jic23@kernel.org> | 2026-05-31 10:59:40 +0100 |
| commit | eaead586b3d95890832449f2887283b067426ecc (patch) | |
| tree | 9f54b004d3b1ae8e5f7055ed25e664941ac646af /drivers | |
| parent | 8bf3e7a9defcfa889976258919d99fa2e8465189 (diff) | |
iio: magnetometer: ak8975: ensure device is awake for buffered capture
Currently, the ak8975_start_read_axis() can be called while the device
is autosuspended, causing two issues:
1. I2C transfers in the aforementioned function will fail or timeout
because ak8975_runtime_suspend() disables the device regulators.
2. Since ak8975_fill_buffer() does not hold runtime references,
ak8975_runtime_suspend() can run concurrently, and since PM callbacks
do not use a locking mechanism, it may cause a race accessing the
control register via the I2C bus.
Fix this issue by adding struct iio_buffer_setup_ops that contains
preenable and postdisable functions to ensure correct that device is
powered on when running a buffered capture.
Fixes: bc11ca4a0b84 ("iio:magnetometer:ak8975: triggered buffer support")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Closes: https://sashiko.dev/#/patchset/20260511-magnetometer-fixes-post-pickup-v7-0-9d910faa28b6%40gmail.com
Cc: <Stable@vger.kernel.org>
Signed-off-by: Joshua Crofts <joshua.crofts1@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/iio/magnetometer/ak8975.c | 24 |
1 files changed, 23 insertions, 1 deletions
diff --git a/drivers/iio/magnetometer/ak8975.c b/drivers/iio/magnetometer/ak8975.c index dbab4d0bba34..0fb2fd03d11c 100644 --- a/drivers/iio/magnetometer/ak8975.c +++ b/drivers/iio/magnetometer/ak8975.c @@ -899,6 +899,28 @@ static irqreturn_t ak8975_handle_trigger(int irq, void *p) return IRQ_HANDLED; } +static int ak8975_buffer_preenable(struct iio_dev *indio_dev) +{ + struct ak8975_data *data = iio_priv(indio_dev); + struct device *dev = &data->client->dev; + + return pm_runtime_resume_and_get(dev); +} + +static int ak8975_buffer_postdisable(struct iio_dev *indio_dev) +{ + struct ak8975_data *data = iio_priv(indio_dev); + struct device *dev = &data->client->dev; + + pm_runtime_put_autosuspend(dev); + + return 0; +} + +static const struct iio_buffer_setup_ops ak8975_buffer_setup_ops = { + .preenable = ak8975_buffer_preenable, + .postdisable = ak8975_buffer_postdisable, +}; static int ak8975_probe(struct i2c_client *client) { const struct i2c_device_id *id = i2c_client_get_device_id(client); @@ -992,7 +1014,7 @@ static int ak8975_probe(struct i2c_client *client) indio_dev->name = name; ret = iio_triggered_buffer_setup(indio_dev, NULL, ak8975_handle_trigger, - NULL); + &ak8975_buffer_setup_ops); if (ret) { dev_err(&client->dev, "triggered buffer setup failed\n"); goto power_off; |