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. Include a
patch to move the startup procedure into a function.
Changes since v7:
- Condense the code a bit by dropping rc2
Changes since v6:
- Use helper instead of the lengthy regmap_read_poll_timeout twice
- Just return dps310_startup in dps310_reset_reinit
Changes since v5:
- Completely rework the second patch to reset and reinit in any
timeout condition, if there haven't been previous timeouts that
failed to recover the chip.
Changes since v4:
- Just check for rc rather than rc < 0 in some cases
- Split declaration and init of rc
Changes since v3:
- Don't check regmap* return codes for < 0
- Fix comment spelling
Changes since v2:
- Add some comments
- Fix the clunky control flow
Changes since v1:
- Separate into two patches
- Rename 'dps310_verify_meas_cfg' to 'dps310_check_reset_meas_cfg'
Eddie James (2):
iio: pressure: dps310: Refactor startup procedure
iio: pressure: dps310: Reset chip after timeout
drivers/iio/pressure/dps310.c | 262 +++++++++++++++++++++-------------
1 file changed, 163 insertions(+), 99 deletions(-)
--
2.31.1
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.
Fixes: ba6ec48e76bc ("iio: Add driver for Infineon DPS310")
Cc: <[email protected]>
Signed-off-by: Eddie James <[email protected]>
Reviewed-by: Andy Shevchenko <[email protected]>
---
drivers/iio/pressure/dps310.c | 74 ++++++++++++++++++++++++++++++-----
1 file changed, 64 insertions(+), 10 deletions(-)
diff --git a/drivers/iio/pressure/dps310.c b/drivers/iio/pressure/dps310.c
index c706a8b423b5..984a3f511a1a 100644
--- a/drivers/iio/pressure/dps310.c
+++ b/drivers/iio/pressure/dps310.c
@@ -89,6 +89,7 @@ struct dps310_data {
s32 c00, c10, c20, c30, c01, c11, c21;
s32 pressure_raw;
s32 temp_raw;
+ bool timeout_recovery_failed;
};
static const struct iio_chan_spec dps310_channels[] = {
@@ -393,11 +394,69 @@ static int dps310_get_temp_k(struct dps310_data *data)
return scale_factors[ilog2(rc)];
}
+static int dps310_reset_wait(struct dps310_data *data)
+{
+ int rc;
+
+ rc = regmap_write(data->regmap, DPS310_RESET, DPS310_RESET_MAGIC);
+ if (rc)
+ return rc;
+
+ /* Wait for device chip access: 2.5ms in specification */
+ usleep_range(2500, 12000);
+ return 0;
+}
+
+static int dps310_reset_reinit(struct dps310_data *data)
+{
+ int rc;
+
+ rc = dps310_reset_wait(data);
+ if (rc)
+ return rc;
+
+ return dps310_startup(data);
+}
+
+static int dps310_ready_status(struct dps310_data *data, int ready_bit, int timeout)
+{
+ int sleep = DPS310_POLL_SLEEP_US(timeout);
+ int ready;
+
+ return regmap_read_poll_timeout(data->regmap, DPS310_MEAS_CFG, ready, ready & ready_bit,
+ sleep, timeout);
+}
+
+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) {
+ /* 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))
+ data->timeout_recovery_failed = true;
+ else
+ return 0;
+ }
+ }
+
+ return rc;
+ }
+
+ data->timeout_recovery_failed = false;
+ return 0;
+}
+
static int dps310_read_pres_raw(struct dps310_data *data)
{
int rc;
int rate;
- int ready;
int timeout;
s32 raw;
u8 val[3];
@@ -409,9 +468,7 @@ static int dps310_read_pres_raw(struct dps310_data *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);
+ rc = dps310_ready(data, DPS310_PRS_RDY, timeout);
if (rc)
goto done;
@@ -448,7 +505,6 @@ static int dps310_read_temp_raw(struct dps310_data *data)
{
int rc;
int rate;
- int ready;
int timeout;
if (mutex_lock_interruptible(&data->lock))
@@ -458,10 +514,8 @@ static int dps310_read_temp_raw(struct dps310_data *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)
+ rc = dps310_ready(data, DPS310_TMP_RDY, timeout);
+ if (rc)
goto done;
rc = dps310_read_temp_ready(data);
@@ -756,7 +810,7 @@ static void dps310_reset(void *action_data)
{
struct dps310_data *data = action_data;
- regmap_write(data->regmap, DPS310_RESET, DPS310_RESET_MAGIC);
+ dps310_reset_wait(data);
}
static const struct regmap_config dps310_regmap_config = {
--
2.31.1
On Thu, Sep 15, 2022 at 10:57 PM Eddie James <[email protected]> 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
On Fri, 16 Sep 2022 16:25:35 +0100
Jonathan Cameron <[email protected]> wrote:
> On Fri, 16 Sep 2022 08:51:13 +0300
> Andy Shevchenko <[email protected]> wrote:
>
> > On Thu, Sep 15, 2022 at 10:57 PM Eddie James <[email protected]> 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.
>
> Hmm.
>
> 1st time around, any other error code would result in us just returning directly
> which is fine.
> 2nd time around I'm not sure we care about what the error code is. Even if
> something else went wrong we failed to recover and the first error
> that lead to that was -ETIMEDOUT.
>
> So I think this is correct as is, be it a little unusual!
Given timing late in the cycle, I've queued this up for the next merge
window rather than rushing it in.
Applied to the togreg branch of iio.git and pushed out as testing.
Note I plan to rebase that branch shortly as I need some stuff that
is in upstream for other series. Hence still time for this discussion to
continue if anyone wants to!
Thanks,
Jonathan
>
> Jonathan
>
> >
> > 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;
> > > +}
> >
>