* [PATCH v4 0/2] iio: pressure: dps310: Reset chip if MEAS_CFG is corrupt
@ 2022-08-09 21:12 Eddie James
2022-08-09 21:12 ` [PATCH v4 1/2] iio: pressure: dps310: Refactor startup procedure Eddie James
2022-08-09 21:12 ` [PATCH v4 2/2] iio: pressure: dps310: Reset chip if MEAS_CFG is corrupt Eddie James
0 siblings, 2 replies; 12+ messages in thread
From: Eddie James @ 2022-08-09 21:12 UTC (permalink / raw)
To: linux-iio; +Cc: jic23, lars, linux-kernel, andy.shevchenko, joel, eajames
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. Include a patch to move the
startup procedure into a function.
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 if MEAS_CFG is corrupt
drivers/iio/pressure/dps310.c | 276 +++++++++++++++++++++-------------
1 file changed, 172 insertions(+), 104 deletions(-)
--
2.31.1
^ permalink raw reply [flat|nested] 12+ messages in thread
* [PATCH v4 1/2] iio: pressure: dps310: Refactor startup procedure
2022-08-09 21:12 [PATCH v4 0/2] iio: pressure: dps310: Reset chip if MEAS_CFG is corrupt Eddie James
@ 2022-08-09 21:12 ` Eddie James
2022-08-12 22:03 ` Andy Shevchenko
2022-08-09 21:12 ` [PATCH v4 2/2] iio: pressure: dps310: Reset chip if MEAS_CFG is corrupt Eddie James
1 sibling, 1 reply; 12+ messages in thread
From: Eddie James @ 2022-08-09 21:12 UTC (permalink / raw)
To: linux-iio; +Cc: jic23, lars, linux-kernel, andy.shevchenko, joel, eajames
Move the startup procedure into a function, and correct a missing
check on the return code for writing the PRS_CFG register.
Signed-off-by: Eddie James <eajames@linux.ibm.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
---
drivers/iio/pressure/dps310.c | 188 ++++++++++++++++++----------------
1 file changed, 99 insertions(+), 89 deletions(-)
diff --git a/drivers/iio/pressure/dps310.c b/drivers/iio/pressure/dps310.c
index 36fb7ae0d0a9..c706a8b423b5 100644
--- a/drivers/iio/pressure/dps310.c
+++ b/drivers/iio/pressure/dps310.c
@@ -159,6 +159,102 @@ static int dps310_get_coefs(struct dps310_data *data)
return 0;
}
+/*
+ * Some versions of the chip will read temperatures in the ~60C range when
+ * it's actually ~20C. This is the manufacturer recommended workaround
+ * to correct the issue. The registers used below are undocumented.
+ */
+static int dps310_temp_workaround(struct dps310_data *data)
+{
+ int rc;
+ int reg;
+
+ rc = regmap_read(data->regmap, 0x32, ®);
+ if (rc)
+ return rc;
+
+ /*
+ * If bit 1 is set then the device is okay, and the workaround does not
+ * need to be applied
+ */
+ if (reg & BIT(1))
+ return 0;
+
+ rc = regmap_write(data->regmap, 0x0e, 0xA5);
+ if (rc)
+ return rc;
+
+ rc = regmap_write(data->regmap, 0x0f, 0x96);
+ if (rc)
+ return rc;
+
+ rc = regmap_write(data->regmap, 0x62, 0x02);
+ if (rc)
+ return rc;
+
+ rc = regmap_write(data->regmap, 0x0e, 0x00);
+ if (rc)
+ return rc;
+
+ return regmap_write(data->regmap, 0x0f, 0x00);
+}
+
+static int dps310_startup(struct dps310_data *data)
+{
+ int rc;
+ int ready;
+
+ /*
+ * Set up pressure sensor in single sample, one measurement per second
+ * mode
+ */
+ rc = regmap_write(data->regmap, DPS310_PRS_CFG, 0);
+ if (rc)
+ return rc;
+
+ /*
+ * Set up external (MEMS) temperature sensor in single sample, one
+ * measurement per second mode
+ */
+ rc = regmap_write(data->regmap, DPS310_TMP_CFG, DPS310_TMP_EXT);
+ if (rc)
+ return rc;
+
+ /* Temp and pressure shifts are disabled when PRC <= 8 */
+ rc = regmap_write_bits(data->regmap, DPS310_CFG_REG,
+ DPS310_PRS_SHIFT_EN | DPS310_TMP_SHIFT_EN, 0);
+ if (rc)
+ return rc;
+
+ /* MEAS_CFG doesn't update correctly unless first written with 0 */
+ rc = regmap_write_bits(data->regmap, DPS310_MEAS_CFG,
+ DPS310_MEAS_CTRL_BITS, 0);
+ if (rc)
+ return rc;
+
+ /* Turn on temperature and pressure measurement in the background */
+ rc = regmap_write_bits(data->regmap, DPS310_MEAS_CFG,
+ DPS310_MEAS_CTRL_BITS, DPS310_PRS_EN |
+ DPS310_TEMP_EN | DPS310_BACKGROUND);
+ if (rc)
+ return rc;
+
+ /*
+ * Calibration coefficients required for reporting temperature.
+ * They are available 40ms after the device has started
+ */
+ rc = regmap_read_poll_timeout(data->regmap, DPS310_MEAS_CFG, ready,
+ ready & DPS310_COEF_RDY, 10000, 40000);
+ if (rc)
+ return rc;
+
+ rc = dps310_get_coefs(data);
+ if (rc)
+ return rc;
+
+ return dps310_temp_workaround(data);
+}
+
static int dps310_get_pres_precision(struct dps310_data *data)
{
int rc;
@@ -677,52 +773,12 @@ static const struct iio_info dps310_info = {
.write_raw = dps310_write_raw,
};
-/*
- * Some verions of chip will read temperatures in the ~60C range when
- * its actually ~20C. This is the manufacturer recommended workaround
- * to correct the issue. The registers used below are undocumented.
- */
-static int dps310_temp_workaround(struct dps310_data *data)
-{
- int rc;
- int reg;
-
- rc = regmap_read(data->regmap, 0x32, ®);
- if (rc < 0)
- return rc;
-
- /*
- * If bit 1 is set then the device is okay, and the workaround does not
- * need to be applied
- */
- if (reg & BIT(1))
- return 0;
-
- rc = regmap_write(data->regmap, 0x0e, 0xA5);
- if (rc < 0)
- return rc;
-
- rc = regmap_write(data->regmap, 0x0f, 0x96);
- if (rc < 0)
- return rc;
-
- rc = regmap_write(data->regmap, 0x62, 0x02);
- if (rc < 0)
- return rc;
-
- rc = regmap_write(data->regmap, 0x0e, 0x00);
- if (rc < 0)
- return rc;
-
- return regmap_write(data->regmap, 0x0f, 0x00);
-}
-
static int dps310_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct dps310_data *data;
struct iio_dev *iio;
- int rc, ready;
+ int rc;
iio = devm_iio_device_alloc(&client->dev, sizeof(*data));
if (!iio)
@@ -747,54 +803,8 @@ static int dps310_probe(struct i2c_client *client,
if (rc)
return rc;
- /*
- * Set up pressure sensor in single sample, one measurement per second
- * mode
- */
- rc = regmap_write(data->regmap, DPS310_PRS_CFG, 0);
-
- /*
- * Set up external (MEMS) temperature sensor in single sample, one
- * measurement per second mode
- */
- rc = regmap_write(data->regmap, DPS310_TMP_CFG, DPS310_TMP_EXT);
- if (rc < 0)
- return rc;
-
- /* Temp and pressure shifts are disabled when PRC <= 8 */
- rc = regmap_write_bits(data->regmap, DPS310_CFG_REG,
- DPS310_PRS_SHIFT_EN | DPS310_TMP_SHIFT_EN, 0);
- if (rc < 0)
- return rc;
-
- /* MEAS_CFG doesn't update correctly unless first written with 0 */
- rc = regmap_write_bits(data->regmap, DPS310_MEAS_CFG,
- DPS310_MEAS_CTRL_BITS, 0);
- if (rc < 0)
- return rc;
-
- /* Turn on temperature and pressure measurement in the background */
- rc = regmap_write_bits(data->regmap, DPS310_MEAS_CFG,
- DPS310_MEAS_CTRL_BITS, DPS310_PRS_EN |
- DPS310_TEMP_EN | DPS310_BACKGROUND);
- if (rc < 0)
- return rc;
-
- /*
- * Calibration coefficients required for reporting temperature.
- * They are available 40ms after the device has started
- */
- rc = regmap_read_poll_timeout(data->regmap, DPS310_MEAS_CFG, ready,
- ready & DPS310_COEF_RDY, 10000, 40000);
- if (rc < 0)
- return rc;
-
- rc = dps310_get_coefs(data);
- if (rc < 0)
- return rc;
-
- rc = dps310_temp_workaround(data);
- if (rc < 0)
+ rc = dps310_startup(data);
+ if (rc)
return rc;
rc = devm_iio_device_register(&client->dev, iio);
--
2.31.1
^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH v4 2/2] iio: pressure: dps310: Reset chip if MEAS_CFG is corrupt
2022-08-09 21:12 [PATCH v4 0/2] iio: pressure: dps310: Reset chip if MEAS_CFG is corrupt Eddie James
2022-08-09 21:12 ` [PATCH v4 1/2] iio: pressure: dps310: Refactor startup procedure Eddie James
@ 2022-08-09 21:12 ` Eddie James
2022-08-12 22:13 ` Andy Shevchenko
1 sibling, 1 reply; 12+ messages in thread
From: Eddie James @ 2022-08-09 21:12 UTC (permalink / raw)
To: linux-iio; +Cc: jic23, lars, linux-kernel, andy.shevchenko, joel, eajames
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 <eajames@linux.ibm.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
---
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
^ permalink raw reply related [flat|nested] 12+ messages in thread
* Re: [PATCH v4 1/2] iio: pressure: dps310: Refactor startup procedure
2022-08-09 21:12 ` [PATCH v4 1/2] iio: pressure: dps310: Refactor startup procedure Eddie James
@ 2022-08-12 22:03 ` Andy Shevchenko
2022-08-15 13:42 ` Eddie James
0 siblings, 1 reply; 12+ messages in thread
From: Andy Shevchenko @ 2022-08-12 22:03 UTC (permalink / raw)
To: Eddie James
Cc: linux-iio, Jonathan Cameron, Lars-Peter Clausen,
Linux Kernel Mailing List, Joel Stanley
On Wed, Aug 10, 2022 at 12:12 AM Eddie James <eajames@linux.ibm.com> wrote:
>
> Move the startup procedure into a function, and correct a missing
> check on the return code for writing the PRS_CFG register.
Code looks good, one remark below.
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
> Signed-off-by: Eddie James <eajames@linux.ibm.com>
> Reviewed-by: Joel Stanley <joel@jms.id.au>
> ---
> drivers/iio/pressure/dps310.c | 188 ++++++++++++++++++----------------
> 1 file changed, 99 insertions(+), 89 deletions(-)
>
> diff --git a/drivers/iio/pressure/dps310.c b/drivers/iio/pressure/dps310.c
> index 36fb7ae0d0a9..c706a8b423b5 100644
> --- a/drivers/iio/pressure/dps310.c
> +++ b/drivers/iio/pressure/dps310.c
> @@ -159,6 +159,102 @@ static int dps310_get_coefs(struct dps310_data *data)
> return 0;
> }
>
> +/*
> + * Some versions of the chip will read temperatures in the ~60C range when
> + * it's actually ~20C. This is the manufacturer recommended workaround
> + * to correct the issue. The registers used below are undocumented.
> + */
> +static int dps310_temp_workaround(struct dps310_data *data)
> +{
> + int rc;
> + int reg;
> +
> + rc = regmap_read(data->regmap, 0x32, ®);
> + if (rc)
> + return rc;
> +
> + /*
> + * If bit 1 is set then the device is okay, and the workaround does not
> + * need to be applied
> + */
> + if (reg & BIT(1))
> + return 0;
> +
> + rc = regmap_write(data->regmap, 0x0e, 0xA5);
> + if (rc)
> + return rc;
> +
> + rc = regmap_write(data->regmap, 0x0f, 0x96);
> + if (rc)
> + return rc;
This code already exists, but still want to ask, is it really
byte-registers here and not be16/le16 one? In such a case perhaps bulk
write can be used to reflect it better?
> + rc = regmap_write(data->regmap, 0x62, 0x02);
> + if (rc)
> + return rc;
> +
> + rc = regmap_write(data->regmap, 0x0e, 0x00);
> + if (rc)
> + return rc;
> +
> + return regmap_write(data->regmap, 0x0f, 0x00);
Ditto.
> +}
> +
> +static int dps310_startup(struct dps310_data *data)
> +{
> + int rc;
> + int ready;
> +
> + /*
> + * Set up pressure sensor in single sample, one measurement per second
> + * mode
> + */
> + rc = regmap_write(data->regmap, DPS310_PRS_CFG, 0);
> + if (rc)
> + return rc;
> +
> + /*
> + * Set up external (MEMS) temperature sensor in single sample, one
> + * measurement per second mode
> + */
> + rc = regmap_write(data->regmap, DPS310_TMP_CFG, DPS310_TMP_EXT);
> + if (rc)
> + return rc;
> +
> + /* Temp and pressure shifts are disabled when PRC <= 8 */
> + rc = regmap_write_bits(data->regmap, DPS310_CFG_REG,
> + DPS310_PRS_SHIFT_EN | DPS310_TMP_SHIFT_EN, 0);
> + if (rc)
> + return rc;
> +
> + /* MEAS_CFG doesn't update correctly unless first written with 0 */
> + rc = regmap_write_bits(data->regmap, DPS310_MEAS_CFG,
> + DPS310_MEAS_CTRL_BITS, 0);
> + if (rc)
> + return rc;
> +
> + /* Turn on temperature and pressure measurement in the background */
> + rc = regmap_write_bits(data->regmap, DPS310_MEAS_CFG,
> + DPS310_MEAS_CTRL_BITS, DPS310_PRS_EN |
> + DPS310_TEMP_EN | DPS310_BACKGROUND);
> + if (rc)
> + return rc;
> +
> + /*
> + * Calibration coefficients required for reporting temperature.
> + * They are available 40ms after the device has started
> + */
> + rc = regmap_read_poll_timeout(data->regmap, DPS310_MEAS_CFG, ready,
> + ready & DPS310_COEF_RDY, 10000, 40000);
> + if (rc)
> + return rc;
> +
> + rc = dps310_get_coefs(data);
> + if (rc)
> + return rc;
> +
> + return dps310_temp_workaround(data);
> +}
> +
> static int dps310_get_pres_precision(struct dps310_data *data)
> {
> int rc;
> @@ -677,52 +773,12 @@ static const struct iio_info dps310_info = {
> .write_raw = dps310_write_raw,
> };
>
> -/*
> - * Some verions of chip will read temperatures in the ~60C range when
> - * its actually ~20C. This is the manufacturer recommended workaround
> - * to correct the issue. The registers used below are undocumented.
> - */
> -static int dps310_temp_workaround(struct dps310_data *data)
> -{
> - int rc;
> - int reg;
> -
> - rc = regmap_read(data->regmap, 0x32, ®);
> - if (rc < 0)
> - return rc;
> -
> - /*
> - * If bit 1 is set then the device is okay, and the workaround does not
> - * need to be applied
> - */
> - if (reg & BIT(1))
> - return 0;
> -
> - rc = regmap_write(data->regmap, 0x0e, 0xA5);
> - if (rc < 0)
> - return rc;
> -
> - rc = regmap_write(data->regmap, 0x0f, 0x96);
> - if (rc < 0)
> - return rc;
> -
> - rc = regmap_write(data->regmap, 0x62, 0x02);
> - if (rc < 0)
> - return rc;
> -
> - rc = regmap_write(data->regmap, 0x0e, 0x00);
> - if (rc < 0)
> - return rc;
> -
> - return regmap_write(data->regmap, 0x0f, 0x00);
> -}
> -
> static int dps310_probe(struct i2c_client *client,
> const struct i2c_device_id *id)
> {
> struct dps310_data *data;
> struct iio_dev *iio;
> - int rc, ready;
> + int rc;
>
> iio = devm_iio_device_alloc(&client->dev, sizeof(*data));
> if (!iio)
> @@ -747,54 +803,8 @@ static int dps310_probe(struct i2c_client *client,
> if (rc)
> return rc;
>
> - /*
> - * Set up pressure sensor in single sample, one measurement per second
> - * mode
> - */
> - rc = regmap_write(data->regmap, DPS310_PRS_CFG, 0);
> -
> - /*
> - * Set up external (MEMS) temperature sensor in single sample, one
> - * measurement per second mode
> - */
> - rc = regmap_write(data->regmap, DPS310_TMP_CFG, DPS310_TMP_EXT);
> - if (rc < 0)
> - return rc;
> -
> - /* Temp and pressure shifts are disabled when PRC <= 8 */
> - rc = regmap_write_bits(data->regmap, DPS310_CFG_REG,
> - DPS310_PRS_SHIFT_EN | DPS310_TMP_SHIFT_EN, 0);
> - if (rc < 0)
> - return rc;
> -
> - /* MEAS_CFG doesn't update correctly unless first written with 0 */
> - rc = regmap_write_bits(data->regmap, DPS310_MEAS_CFG,
> - DPS310_MEAS_CTRL_BITS, 0);
> - if (rc < 0)
> - return rc;
> -
> - /* Turn on temperature and pressure measurement in the background */
> - rc = regmap_write_bits(data->regmap, DPS310_MEAS_CFG,
> - DPS310_MEAS_CTRL_BITS, DPS310_PRS_EN |
> - DPS310_TEMP_EN | DPS310_BACKGROUND);
> - if (rc < 0)
> - return rc;
> -
> - /*
> - * Calibration coefficients required for reporting temperature.
> - * They are available 40ms after the device has started
> - */
> - rc = regmap_read_poll_timeout(data->regmap, DPS310_MEAS_CFG, ready,
> - ready & DPS310_COEF_RDY, 10000, 40000);
> - if (rc < 0)
> - return rc;
> -
> - rc = dps310_get_coefs(data);
> - if (rc < 0)
> - return rc;
> -
> - rc = dps310_temp_workaround(data);
> - if (rc < 0)
> + rc = dps310_startup(data);
> + if (rc)
> return rc;
>
> rc = devm_iio_device_register(&client->dev, iio);
> --
> 2.31.1
>
--
With Best Regards,
Andy Shevchenko
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v4 2/2] iio: pressure: dps310: Reset chip if MEAS_CFG is corrupt
2022-08-09 21:12 ` [PATCH v4 2/2] iio: pressure: dps310: Reset chip if MEAS_CFG is corrupt Eddie James
@ 2022-08-12 22:13 ` Andy Shevchenko
2022-08-15 13:59 ` Eddie James
0 siblings, 1 reply; 12+ messages in thread
From: Andy Shevchenko @ 2022-08-12 22:13 UTC (permalink / raw)
To: Eddie James
Cc: linux-iio, Jonathan Cameron, Lars-Peter Clausen,
Linux Kernel Mailing List, Joel Stanley
On Wed, Aug 10, 2022 at 12:12 AM Eddie James <eajames@linux.ibm.com> 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
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v4 1/2] iio: pressure: dps310: Refactor startup procedure
2022-08-12 22:03 ` Andy Shevchenko
@ 2022-08-15 13:42 ` Eddie James
2022-08-19 9:42 ` Andy Shevchenko
0 siblings, 1 reply; 12+ messages in thread
From: Eddie James @ 2022-08-15 13:42 UTC (permalink / raw)
To: Andy Shevchenko
Cc: linux-iio, Jonathan Cameron, Lars-Peter Clausen,
Linux Kernel Mailing List, Joel Stanley
On 8/12/22 17:03, Andy Shevchenko wrote:
> On Wed, Aug 10, 2022 at 12:12 AM Eddie James <eajames@linux.ibm.com> wrote:
>> Move the startup procedure into a function, and correct a missing
>> check on the return code for writing the PRS_CFG register.
> Code looks good, one remark below.
> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
>
>> Signed-off-by: Eddie James <eajames@linux.ibm.com>
>> Reviewed-by: Joel Stanley <joel@jms.id.au>
>> ---
>> drivers/iio/pressure/dps310.c | 188 ++++++++++++++++++----------------
>> 1 file changed, 99 insertions(+), 89 deletions(-)
>>
>> diff --git a/drivers/iio/pressure/dps310.c b/drivers/iio/pressure/dps310.c
>> index 36fb7ae0d0a9..c706a8b423b5 100644
>> --- a/drivers/iio/pressure/dps310.c
>> +++ b/drivers/iio/pressure/dps310.c
>> @@ -159,6 +159,102 @@ static int dps310_get_coefs(struct dps310_data *data)
>> return 0;
>> }
>>
>> +/*
>> + * Some versions of the chip will read temperatures in the ~60C range when
>> + * it's actually ~20C. This is the manufacturer recommended workaround
>> + * to correct the issue. The registers used below are undocumented.
>> + */
>> +static int dps310_temp_workaround(struct dps310_data *data)
>> +{
>> + int rc;
>> + int reg;
>> +
>> + rc = regmap_read(data->regmap, 0x32, ®);
>> + if (rc)
>> + return rc;
>> +
>> + /*
>> + * If bit 1 is set then the device is okay, and the workaround does not
>> + * need to be applied
>> + */
>> + if (reg & BIT(1))
>> + return 0;
>> +
>> + rc = regmap_write(data->regmap, 0x0e, 0xA5);
>> + if (rc)
>> + return rc;
>> +
>> + rc = regmap_write(data->regmap, 0x0f, 0x96);
>> + if (rc)
>> + return rc;
> This code already exists, but still want to ask, is it really
> byte-registers here and not be16/le16 one? In such a case perhaps bulk
> write can be used to reflect it better?
The temperature and pressure regs are 24 bits big endian, and all the
rest are 8 bits. I think the existing approach is best.
Thanks Andy!
>
>> + rc = regmap_write(data->regmap, 0x62, 0x02);
>> + if (rc)
>> + return rc;
>> +
>> + rc = regmap_write(data->regmap, 0x0e, 0x00);
>> + if (rc)
>> + return rc;
>> +
>> + return regmap_write(data->regmap, 0x0f, 0x00);
> Ditto.
>
>> +}
>> +
>> +static int dps310_startup(struct dps310_data *data)
>> +{
>> + int rc;
>> + int ready;
>> +
>> + /*
>> + * Set up pressure sensor in single sample, one measurement per second
>> + * mode
>> + */
>> + rc = regmap_write(data->regmap, DPS310_PRS_CFG, 0);
>> + if (rc)
>> + return rc;
>> +
>> + /*
>> + * Set up external (MEMS) temperature sensor in single sample, one
>> + * measurement per second mode
>> + */
>> + rc = regmap_write(data->regmap, DPS310_TMP_CFG, DPS310_TMP_EXT);
>> + if (rc)
>> + return rc;
>> +
>> + /* Temp and pressure shifts are disabled when PRC <= 8 */
>> + rc = regmap_write_bits(data->regmap, DPS310_CFG_REG,
>> + DPS310_PRS_SHIFT_EN | DPS310_TMP_SHIFT_EN, 0);
>> + if (rc)
>> + return rc;
>> +
>> + /* MEAS_CFG doesn't update correctly unless first written with 0 */
>> + rc = regmap_write_bits(data->regmap, DPS310_MEAS_CFG,
>> + DPS310_MEAS_CTRL_BITS, 0);
>> + if (rc)
>> + return rc;
>> +
>> + /* Turn on temperature and pressure measurement in the background */
>> + rc = regmap_write_bits(data->regmap, DPS310_MEAS_CFG,
>> + DPS310_MEAS_CTRL_BITS, DPS310_PRS_EN |
>> + DPS310_TEMP_EN | DPS310_BACKGROUND);
>> + if (rc)
>> + return rc;
>> +
>> + /*
>> + * Calibration coefficients required for reporting temperature.
>> + * They are available 40ms after the device has started
>> + */
>> + rc = regmap_read_poll_timeout(data->regmap, DPS310_MEAS_CFG, ready,
>> + ready & DPS310_COEF_RDY, 10000, 40000);
>> + if (rc)
>> + return rc;
>> +
>> + rc = dps310_get_coefs(data);
>> + if (rc)
>> + return rc;
>> +
>> + return dps310_temp_workaround(data);
>> +}
>> +
>> static int dps310_get_pres_precision(struct dps310_data *data)
>> {
>> int rc;
>> @@ -677,52 +773,12 @@ static const struct iio_info dps310_info = {
>> .write_raw = dps310_write_raw,
>> };
>>
>> -/*
>> - * Some verions of chip will read temperatures in the ~60C range when
>> - * its actually ~20C. This is the manufacturer recommended workaround
>> - * to correct the issue. The registers used below are undocumented.
>> - */
>> -static int dps310_temp_workaround(struct dps310_data *data)
>> -{
>> - int rc;
>> - int reg;
>> -
>> - rc = regmap_read(data->regmap, 0x32, ®);
>> - if (rc < 0)
>> - return rc;
>> -
>> - /*
>> - * If bit 1 is set then the device is okay, and the workaround does not
>> - * need to be applied
>> - */
>> - if (reg & BIT(1))
>> - return 0;
>> -
>> - rc = regmap_write(data->regmap, 0x0e, 0xA5);
>> - if (rc < 0)
>> - return rc;
>> -
>> - rc = regmap_write(data->regmap, 0x0f, 0x96);
>> - if (rc < 0)
>> - return rc;
>> -
>> - rc = regmap_write(data->regmap, 0x62, 0x02);
>> - if (rc < 0)
>> - return rc;
>> -
>> - rc = regmap_write(data->regmap, 0x0e, 0x00);
>> - if (rc < 0)
>> - return rc;
>> -
>> - return regmap_write(data->regmap, 0x0f, 0x00);
>> -}
>> -
>> static int dps310_probe(struct i2c_client *client,
>> const struct i2c_device_id *id)
>> {
>> struct dps310_data *data;
>> struct iio_dev *iio;
>> - int rc, ready;
>> + int rc;
>>
>> iio = devm_iio_device_alloc(&client->dev, sizeof(*data));
>> if (!iio)
>> @@ -747,54 +803,8 @@ static int dps310_probe(struct i2c_client *client,
>> if (rc)
>> return rc;
>>
>> - /*
>> - * Set up pressure sensor in single sample, one measurement per second
>> - * mode
>> - */
>> - rc = regmap_write(data->regmap, DPS310_PRS_CFG, 0);
>> -
>> - /*
>> - * Set up external (MEMS) temperature sensor in single sample, one
>> - * measurement per second mode
>> - */
>> - rc = regmap_write(data->regmap, DPS310_TMP_CFG, DPS310_TMP_EXT);
>> - if (rc < 0)
>> - return rc;
>> -
>> - /* Temp and pressure shifts are disabled when PRC <= 8 */
>> - rc = regmap_write_bits(data->regmap, DPS310_CFG_REG,
>> - DPS310_PRS_SHIFT_EN | DPS310_TMP_SHIFT_EN, 0);
>> - if (rc < 0)
>> - return rc;
>> -
>> - /* MEAS_CFG doesn't update correctly unless first written with 0 */
>> - rc = regmap_write_bits(data->regmap, DPS310_MEAS_CFG,
>> - DPS310_MEAS_CTRL_BITS, 0);
>> - if (rc < 0)
>> - return rc;
>> -
>> - /* Turn on temperature and pressure measurement in the background */
>> - rc = regmap_write_bits(data->regmap, DPS310_MEAS_CFG,
>> - DPS310_MEAS_CTRL_BITS, DPS310_PRS_EN |
>> - DPS310_TEMP_EN | DPS310_BACKGROUND);
>> - if (rc < 0)
>> - return rc;
>> -
>> - /*
>> - * Calibration coefficients required for reporting temperature.
>> - * They are available 40ms after the device has started
>> - */
>> - rc = regmap_read_poll_timeout(data->regmap, DPS310_MEAS_CFG, ready,
>> - ready & DPS310_COEF_RDY, 10000, 40000);
>> - if (rc < 0)
>> - return rc;
>> -
>> - rc = dps310_get_coefs(data);
>> - if (rc < 0)
>> - return rc;
>> -
>> - rc = dps310_temp_workaround(data);
>> - if (rc < 0)
>> + rc = dps310_startup(data);
>> + if (rc)
>> return rc;
>>
>> rc = devm_iio_device_register(&client->dev, iio);
>> --
>> 2.31.1
>>
>
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v4 2/2] iio: pressure: dps310: Reset chip if MEAS_CFG is corrupt
2022-08-12 22:13 ` Andy Shevchenko
@ 2022-08-15 13:59 ` Eddie James
2022-08-20 11:50 ` Jonathan Cameron
0 siblings, 1 reply; 12+ messages in thread
From: Eddie James @ 2022-08-15 13:59 UTC (permalink / raw)
To: Andy Shevchenko
Cc: linux-iio, Jonathan Cameron, Lars-Peter Clausen,
Linux Kernel Mailing List, Joel Stanley
On 8/12/22 17:13, Andy Shevchenko wrote:
> On Wed, Aug 10, 2022 at 12:12 AM Eddie James <eajames@linux.ibm.com> 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);
>
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v4 1/2] iio: pressure: dps310: Refactor startup procedure
2022-08-15 13:42 ` Eddie James
@ 2022-08-19 9:42 ` Andy Shevchenko
2022-08-20 11:49 ` Jonathan Cameron
0 siblings, 1 reply; 12+ messages in thread
From: Andy Shevchenko @ 2022-08-19 9:42 UTC (permalink / raw)
To: Eddie James
Cc: linux-iio, Jonathan Cameron, Lars-Peter Clausen,
Linux Kernel Mailing List, Joel Stanley
On Mon, Aug 15, 2022 at 4:42 PM Eddie James <eajames@linux.ibm.com> wrote:
> On 8/12/22 17:03, Andy Shevchenko wrote:
> > On Wed, Aug 10, 2022 at 12:12 AM Eddie James <eajames@linux.ibm.com> wrote:
...
> >> + rc = regmap_write(data->regmap, 0x0e, 0xA5);
> >> + if (rc)
> >> + return rc;
> >> +
> >> + rc = regmap_write(data->regmap, 0x0f, 0x96);
> >> + if (rc)
> >> + return rc;
> > This code already exists, but still want to ask, is it really
> > byte-registers here and not be16/le16 one? In such a case perhaps bulk
> > write can be used to reflect it better?
>
> The temperature and pressure regs are 24 bits big endian, and all the
> rest are 8 bits. I think the existing approach is best.
It doesn't look like you got what I was meaning... Or I misunderstood
what you said.
The code above writes two byte values to two sequential registers
which make me think that they are 16-bit registers at offset 0x0e.
...
> >> + rc = regmap_write(data->regmap, 0x0e, 0x00);
> >> + if (rc)
> >> + return rc;
> >> +
> >> + return regmap_write(data->regmap, 0x0f, 0x00);
Ditto.
--
With Best Regards,
Andy Shevchenko
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v4 1/2] iio: pressure: dps310: Refactor startup procedure
2022-08-19 9:42 ` Andy Shevchenko
@ 2022-08-20 11:49 ` Jonathan Cameron
2022-09-06 19:48 ` Eddie James
0 siblings, 1 reply; 12+ messages in thread
From: Jonathan Cameron @ 2022-08-20 11:49 UTC (permalink / raw)
To: Andy Shevchenko
Cc: Eddie James, linux-iio, Lars-Peter Clausen,
Linux Kernel Mailing List, Joel Stanley
On Fri, 19 Aug 2022 12:42:00 +0300
Andy Shevchenko <andy.shevchenko@gmail.com> wrote:
> On Mon, Aug 15, 2022 at 4:42 PM Eddie James <eajames@linux.ibm.com> wrote:
> > On 8/12/22 17:03, Andy Shevchenko wrote:
> > > On Wed, Aug 10, 2022 at 12:12 AM Eddie James <eajames@linux.ibm.com> wrote:
>
> ...
>
> > >> + rc = regmap_write(data->regmap, 0x0e, 0xA5);
> > >> + if (rc)
> > >> + return rc;
> > >> +
> > >> + rc = regmap_write(data->regmap, 0x0f, 0x96);
> > >> + if (rc)
> > >> + return rc;
> > > This code already exists, but still want to ask, is it really
> > > byte-registers here and not be16/le16 one? In such a case perhaps bulk
> > > write can be used to reflect it better?
> >
> > The temperature and pressure regs are 24 bits big endian, and all the
> > rest are 8 bits. I think the existing approach is best.
>
> It doesn't look like you got what I was meaning... Or I misunderstood
> what you said.
>
> The code above writes two byte values to two sequential registers
> which make me think that they are 16-bit registers at offset 0x0e.
Given they are undocumented, this is guessing territory.
Probably best to just leave them as is.
You could do a bulk write on an array though as that implies
nothing about what's in the registers -just that they happen
to be next to each other.
>
> ...
>
> > >> + rc = regmap_write(data->regmap, 0x0e, 0x00);
> > >> + if (rc)
> > >> + return rc;
> > >> +
> > >> + return regmap_write(data->regmap, 0x0f, 0x00);
>
> Ditto.
>
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v4 2/2] iio: pressure: dps310: Reset chip if MEAS_CFG is corrupt
2022-08-15 13:59 ` Eddie James
@ 2022-08-20 11:50 ` Jonathan Cameron
0 siblings, 0 replies; 12+ messages in thread
From: Jonathan Cameron @ 2022-08-20 11:50 UTC (permalink / raw)
To: Eddie James
Cc: Andy Shevchenko, linux-iio, Lars-Peter Clausen,
Linux Kernel Mailing List, Joel Stanley
On Mon, 15 Aug 2022 08:59:03 -0500
Eddie James <eajames@linux.ibm.com> wrote:
> On 8/12/22 17:13, Andy Shevchenko wrote:
> > On Wed, Aug 10, 2022 at 12:12 AM Eddie James <eajames@linux.ibm.com> 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
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v4 1/2] iio: pressure: dps310: Refactor startup procedure
2022-08-20 11:49 ` Jonathan Cameron
@ 2022-09-06 19:48 ` Eddie James
2022-09-11 9:56 ` Jonathan Cameron
0 siblings, 1 reply; 12+ messages in thread
From: Eddie James @ 2022-09-06 19:48 UTC (permalink / raw)
To: Jonathan Cameron, Andy Shevchenko
Cc: linux-iio, Lars-Peter Clausen, Linux Kernel Mailing List, Joel Stanley
On 8/20/22 06:49, Jonathan Cameron wrote:
> On Fri, 19 Aug 2022 12:42:00 +0300
> Andy Shevchenko <andy.shevchenko@gmail.com> wrote:
>
>> On Mon, Aug 15, 2022 at 4:42 PM Eddie James <eajames@linux.ibm.com> wrote:
>>> On 8/12/22 17:03, Andy Shevchenko wrote:
>>>> On Wed, Aug 10, 2022 at 12:12 AM Eddie James <eajames@linux.ibm.com> wrote:
>> ...
>>
>>>>> + rc = regmap_write(data->regmap, 0x0e, 0xA5);
>>>>> + if (rc)
>>>>> + return rc;
>>>>> +
>>>>> + rc = regmap_write(data->regmap, 0x0f, 0x96);
>>>>> + if (rc)
>>>>> + return rc;
>>>> This code already exists, but still want to ask, is it really
>>>> byte-registers here and not be16/le16 one? In such a case perhaps bulk
>>>> write can be used to reflect it better?
>>> The temperature and pressure regs are 24 bits big endian, and all the
>>> rest are 8 bits. I think the existing approach is best.
>> It doesn't look like you got what I was meaning... Or I misunderstood
>> what you said.
>>
>> The code above writes two byte values to two sequential registers
>> which make me think that they are 16-bit registers at offset 0x0e.
> Given they are undocumented, this is guessing territory.
> Probably best to just leave them as is.
> You could do a bulk write on an array though as that implies
> nothing about what's in the registers -just that they happen
> to be next to each other.
Indeed. Is it worth it to switch to bulk write for two 2-byte writes?
I'm inclined to say no and will leave this as-is for v6, but if you
think it is, I can switch it.
Thanks,
Eddie
>
>> ...
>>
>>>>> + rc = regmap_write(data->regmap, 0x0e, 0x00);
>>>>> + if (rc)
>>>>> + return rc;
>>>>> +
>>>>> + return regmap_write(data->regmap, 0x0f, 0x00);
>> Ditto.
>>
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v4 1/2] iio: pressure: dps310: Refactor startup procedure
2022-09-06 19:48 ` Eddie James
@ 2022-09-11 9:56 ` Jonathan Cameron
0 siblings, 0 replies; 12+ messages in thread
From: Jonathan Cameron @ 2022-09-11 9:56 UTC (permalink / raw)
To: Eddie James
Cc: Andy Shevchenko, linux-iio, Lars-Peter Clausen,
Linux Kernel Mailing List, Joel Stanley
On Tue, 6 Sep 2022 14:48:20 -0500
Eddie James <eajames@linux.ibm.com> wrote:
> On 8/20/22 06:49, Jonathan Cameron wrote:
> > On Fri, 19 Aug 2022 12:42:00 +0300
> > Andy Shevchenko <andy.shevchenko@gmail.com> wrote:
> >
> >> On Mon, Aug 15, 2022 at 4:42 PM Eddie James <eajames@linux.ibm.com> wrote:
> >>> On 8/12/22 17:03, Andy Shevchenko wrote:
> >>>> On Wed, Aug 10, 2022 at 12:12 AM Eddie James <eajames@linux.ibm.com> wrote:
> >> ...
> >>
> >>>>> + rc = regmap_write(data->regmap, 0x0e, 0xA5);
> >>>>> + if (rc)
> >>>>> + return rc;
> >>>>> +
> >>>>> + rc = regmap_write(data->regmap, 0x0f, 0x96);
> >>>>> + if (rc)
> >>>>> + return rc;
> >>>> This code already exists, but still want to ask, is it really
> >>>> byte-registers here and not be16/le16 one? In such a case perhaps bulk
> >>>> write can be used to reflect it better?
> >>> The temperature and pressure regs are 24 bits big endian, and all the
> >>> rest are 8 bits. I think the existing approach is best.
> >> It doesn't look like you got what I was meaning... Or I misunderstood
> >> what you said.
> >>
> >> The code above writes two byte values to two sequential registers
> >> which make me think that they are 16-bit registers at offset 0x0e.
> > Given they are undocumented, this is guessing territory.
> > Probably best to just leave them as is.
> > You could do a bulk write on an array though as that implies
> > nothing about what's in the registers -just that they happen
> > to be next to each other.
>
>
> Indeed. Is it worth it to switch to bulk write for two 2-byte writes?
> I'm inclined to say no and will leave this as-is for v6, but if you
> think it is, I can switch it.
>
As far as I'm concerned, fine either way.
Jonathan
>
> Thanks,
>
> Eddie
>
>
> >
> >> ...
> >>
> >>>>> + rc = regmap_write(data->regmap, 0x0e, 0x00);
> >>>>> + if (rc)
> >>>>> + return rc;
> >>>>> +
> >>>>> + return regmap_write(data->regmap, 0x0f, 0x00);
> >> Ditto.
> >>
^ permalink raw reply [flat|nested] 12+ messages in thread
end of thread, other threads:[~2022-09-11 10:30 UTC | newest]
Thread overview: 12+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-08-09 21:12 [PATCH v4 0/2] iio: pressure: dps310: Reset chip if MEAS_CFG is corrupt Eddie James
2022-08-09 21:12 ` [PATCH v4 1/2] iio: pressure: dps310: Refactor startup procedure Eddie James
2022-08-12 22:03 ` Andy Shevchenko
2022-08-15 13:42 ` Eddie James
2022-08-19 9:42 ` Andy Shevchenko
2022-08-20 11:49 ` Jonathan Cameron
2022-09-06 19:48 ` Eddie James
2022-09-11 9:56 ` Jonathan Cameron
2022-08-09 21:12 ` [PATCH v4 2/2] iio: pressure: dps310: Reset chip if MEAS_CFG is corrupt Eddie James
2022-08-12 22:13 ` Andy Shevchenko
2022-08-15 13:59 ` Eddie James
2022-08-20 11:50 ` Jonathan Cameron
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