On Wed, Aug 10, 2022 at 12:12 AM Eddie James <eajames@xxxxxxxxxxxxx> wrote:
>
> Corruption of the MEAS_CFG register has been observed soon after
> system boot. In order to recover this scenario, check MEAS_CFG if
> measurement isn't ready, and if it's incorrect, reset the DPS310
> and execute the startup procedure.
Looks like both patches miss the Fixes tag. Can you add them?
...
> +/*
> + * Called with lock held. Returns a negative value on error, a positive value
> + * when the device is not ready, and zero when the device is ready.
> + */
> +static int dps310_check_reset_meas_cfg(struct dps310_data *data, int ready_bit)
> +{
> + int meas_cfg;
> + int rc = regmap_read(data->regmap, DPS310_MEAS_CFG, &meas_cfg);
> +
> + if (rc < 0)
> + return rc;
Please, split definition and assignment.
> + /* Device is ready, proceed to measurement */
> + if (meas_cfg & ready_bit)
> + return 0;
> +
> + /* Device is OK, just not ready */
> + if (meas_cfg & (DPS310_PRS_EN | DPS310_TEMP_EN | DPS310_BACKGROUND))
> + return 1;
> +
> + /* DPS310 register state corrupt, better start from scratch */
> + rc = regmap_write(data->regmap, DPS310_RESET, DPS310_RESET_MAGIC);
> + if (rc < 0)
> + return rc;
> +
> + /* Wait for device chip access: 2.5ms in specification */
> + usleep_range(2500, 12000);
> +
> + /* Reinitialize the chip */
> + rc = dps310_startup(data);
> + if (rc)
> + return rc;
> +
> + dev_info(&data->client->dev,
> + "recovered from corrupted MEAS_CFG=%02x\n", meas_cfg);
> + return 1;
> +}
> +
> static int dps310_read_pres_raw(struct dps310_data *data)
> {
> int rc;
> @@ -405,16 +443,26 @@ static int dps310_read_pres_raw(struct dps310_data *data)
> if (mutex_lock_interruptible(&data->lock))
> return -EINTR;
>
> - rate = dps310_get_pres_samp_freq(data);
> - timeout = DPS310_POLL_TIMEOUT_US(rate);
> -
> - /* Poll for sensor readiness; base the timeout upon the sample rate. */
> - rc = regmap_read_poll_timeout(data->regmap, DPS310_MEAS_CFG, ready,
> - ready & DPS310_PRS_RDY,
> - DPS310_POLL_SLEEP_US(timeout), timeout);
> - if (rc)
> + rc = dps310_check_reset_meas_cfg(data, DPS310_PRS_RDY);
> + if (rc < 0)
> goto done;
>
> + if (rc > 0) {
> + rate = dps310_get_pres_samp_freq(data);
> + timeout = DPS310_POLL_TIMEOUT_US(rate);
> +
> + /*
> + * Poll for sensor readiness; base the timeout upon the sample
> + * rate.
> + */
> + rc = regmap_read_poll_timeout(data->regmap, DPS310_MEAS_CFG,
> + ready, ready & DPS310_PRS_RDY,
> + DPS310_POLL_SLEEP_US(timeout),
> + timeout);
> + if (rc)
> + goto done;
> + }
If you split the condition body to a helper, it can be rewritten like
(also note special definition for positive returned numbers):
rc = ..._reset_meas_cfg(...);
if (rc == DPS310_MEAS_NOT_READY)
rc = ..._new_helper_func(...);
if (rc)
goto done;
and looking at this it might be worth considering calling that
conditional in the middle in the _reset_meas_cfg(), so the latter will
return either 0 or negative error code.
> + rc = dps310_check_reset_meas_cfg(data, DPS310_TMP_RDY);
> if (rc < 0)
> goto done;
>
> + if (rc > 0) {
> + rate = dps310_get_temp_samp_freq(data);
Okay, I see this function is different, but still you may realize a
helper from below and something like above suggestion can still be
achieved.
> + timeout = DPS310_POLL_TIMEOUT_US(rate);
> +
> + /*
> + * Poll for sensor readiness; base the timeout upon the sample
> + * rate.
> + */
> + rc = regmap_read_poll_timeout(data->regmap, DPS310_MEAS_CFG,
> + ready, ready & DPS310_TMP_RDY,
> + DPS310_POLL_SLEEP_US(timeout),
> + timeout);
> + if (rc < 0)
Why out of a sudden ' < 0'?
> + goto done;
> + }
As per above.
> rc = dps310_read_temp_ready(data);
--
With Best Regards,
Andy Shevchenko
