Re: [PATCH v8 2/2] iio: pressure: dps310: Reset chip after timeout

Andy Shevchenko
2022-09-16T05:51:56Z

On Thu, Sep 15, 2022 at 10:57 PM Eddie James <eajames@linux.ibm.com> wrote:
>
> The DPS310 chip has been observed to get "stuck" such that pressure
> and temperature measurements are never indicated as "ready" in the
> MEAS_CFG register. The only solution is to reset the device and try
> again. In order to avoid continual failures, use a boolean flag to
> only try the reset after timeout once if errors persist.

...

> +static int dps310_ready(struct dps310_data *data, int ready_bit, int timeout)
> +{
> + int rc;
> +
> + rc = dps310_ready_status(data, ready_bit, timeout);
> + if (rc) {

> + if (rc == -ETIMEDOUT && !data->timeout_recovery_failed) {

Here you compare rc with a certain error code...

> + /* Reset and reinitialize the chip. */
> + if (dps310_reset_reinit(data)) {
> + data->timeout_recovery_failed = true;
> + } else {
> + /* Try again to get sensor ready status. */

> + if (dps310_ready_status(data, ready_bit, timeout))

...but here you assume that the only error code is -ETIMEDOUT. It's
kinda inconsistent (if you rely on internals of ready_status, then why
to check the certain error code, or otherwise why not to return a real
second error code). That's why I asked about re-using rc here.

In any case I don't think this justifies a v9, let's wait for your
answer and Jonathan's opinion.

> + data->timeout_recovery_failed = true;
> + else
> + return 0;
> + }
> + }
> +
> + return rc;
> + }
> +
> + data->timeout_recovery_failed = false;
> + return 0;
> +}

--
With Best Regards,
Andy Shevchenko