On Thu, 24 Jun 2021 11:19:24 +0300
Alexandru Ardelean <aardelean@xxxxxxxxxxx> wrote:
> When the device is probed, there's no guarantee that the device is not in
> power-down mode. This can happen if the driver is unregistered and
> re-probed.
>
> To make sure this doesn't happen, the value of the TMP006_CONFIG register
> (which is read in the probe function and stored in the device's private
> data) is being checked to see if the MOD bits have the correct value.
>
> This is a fix for a somewhat-rare corner case. As it stands, this doesn't
> look like a high priority to go into the Fixes route.
>
> Signed-off-by: Alexandru Ardelean <aardelean@xxxxxxxxxxx>
This one 'looks' right and as it's been on the list a while I'll apply it.
Would be great if anyone can test it though!
Series applied.
Thanks,
Jonathan
> ---
> drivers/iio/temperature/tmp006.c | 33 +++++++++++++++++++++-----------
> 1 file changed, 22 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/iio/temperature/tmp006.c b/drivers/iio/temperature/tmp006.c
> index db1ac6029c27..e4943a0bc9aa 100644
> --- a/drivers/iio/temperature/tmp006.c
> +++ b/drivers/iio/temperature/tmp006.c
> @@ -193,15 +193,23 @@ static bool tmp006_check_identification(struct i2c_client *client)
> return mid == TMP006_MANUFACTURER_MAGIC && did == TMP006_DEVICE_MAGIC;
> }
>
> -static int tmp006_powerdown(struct tmp006_data *data)
> +static int tmp006_power(struct device *dev, bool up)
> {
> + struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
> + struct tmp006_data *data = iio_priv(indio_dev);
> +
> + if (up)
> + data->config |= TMP006_CONFIG_MOD_MASK;
> + else
> + data->config &= ~TMP006_CONFIG_MOD_MASK;
> +
> return i2c_smbus_write_word_swapped(data->client, TMP006_CONFIG,
> - data->config & ~TMP006_CONFIG_MOD_MASK);
> + data->config);
> }
>
> -static void tmp006_powerdown_cleanup(void *data)
> +static void tmp006_powerdown_cleanup(void *dev)
> {
> - tmp006_powerdown(data);
> + tmp006_power(dev, false);
> }
>
> static int tmp006_probe(struct i2c_client *client,
> @@ -239,7 +247,14 @@ static int tmp006_probe(struct i2c_client *client,
> return ret;
> data->config = ret;
>
> - ret = devm_add_action(&client->dev, tmp006_powerdown_cleanup, data);
> + if ((ret & TMP006_CONFIG_MOD_MASK) != TMP006_CONFIG_MOD_MASK) {
> + ret = tmp006_power(&client->dev, true);
> + if (ret < 0)
> + return ret;
> + }
> +
> + ret = devm_add_action_or_reset(&client->dev, tmp006_powerdown_cleanup,
> + &client->dev);
> if (ret < 0)
> return ret;
>
> @@ -249,16 +264,12 @@ static int tmp006_probe(struct i2c_client *client,
> #ifdef CONFIG_PM_SLEEP
> static int tmp006_suspend(struct device *dev)
> {
> - struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
> - return tmp006_powerdown(iio_priv(indio_dev));
> + return tmp006_power(dev, false);
> }
>
> static int tmp006_resume(struct device *dev)
> {
> - struct tmp006_data *data = iio_priv(i2c_get_clientdata(
> - to_i2c_client(dev)));
> - return i2c_smbus_write_word_swapped(data->client, TMP006_CONFIG,
> - data->config | TMP006_CONFIG_MOD_MASK);
> + return tmp006_power(dev, true);
> }
> #endif
>
