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

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;
  

+}