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.
Signed-off-by: Eddie James <[email protected]>
Reviewed-by: Joel Stanley <[email protected]>
---
drivers/iio/pressure/dps310.c | 88 +++++++++++++++++++++++++++++------
1 file changed, 73 insertions(+), 15 deletions(-)
diff --git a/drivers/iio/pressure/dps310.c b/drivers/iio/pressure/dps310.c
index c706a8b423b5..3a1aeeea3cdd 100644
--- a/drivers/iio/pressure/dps310.c
+++ b/drivers/iio/pressure/dps310.c
@@ -393,6 +393,44 @@ static int dps310_get_temp_k(struct dps310_data *data)
return scale_factors[ilog2(rc)];
}
+/*
+ * 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;
+
+ /* 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;
+ }
+
rc = regmap_bulk_read(data->regmap, DPS310_PRS_BASE, val, sizeof(val));
if (rc < 0)
goto done;
@@ -454,16 +502,26 @@ static int dps310_read_temp_raw(struct dps310_data *data)
if (mutex_lock_interruptible(&data->lock))
return -EINTR;
- rate = dps310_get_temp_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_TMP_RDY,
- DPS310_POLL_SLEEP_US(timeout), timeout);
+ 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);
+ 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)
+ goto done;
+ }
+
rc = dps310_read_temp_ready(data);
done:
--
2.31.1
On Wed, Aug 10, 2022 at 12:12 AM Eddie James <[email protected]> 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
On 8/12/22 17:13, Andy Shevchenko wrote:
> On Wed, Aug 10, 2022 at 12:12 AM Eddie James <[email protected]> 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?
Well this isn't really a software fix - there's no identifiable bug in
the driver. Just trying to recover the chip in this observed mystery
scenario.
>
> ...
>
>> +/*
>> + * 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.
Ack.
>
>> + /* 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.
To be honest that looks more complicated than the way it is now? And I
don't think I can make it common between the temp and pressure without
some complicated macro business.
>
>> + 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'?
Good point, I'll fix that.
>
>> + goto done;
>> + }
> As per above.
>
>> rc = dps310_read_temp_ready(data);
>
On Mon, 15 Aug 2022 08:59:03 -0500
Eddie James <[email protected]> wrote:
> On 8/12/22 17:13, Andy Shevchenko wrote:
> > On Wed, Aug 10, 2022 at 12:12 AM Eddie James <[email protected]> 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?
>
>
> Well this isn't really a software fix - there's no identifiable bug in
> the driver. Just trying to recover the chip in this observed mystery
> scenario.
The tag is useful as well for where to backport this to.
Probably just tag the driver introduction.
Your description makes it clear we aren't finding faults in the
driver - just that it didn't cover this undocumented case!
Jonathan