On 9/10/23 16:22, Jonathan Cameron wrote:
> On Wed, 6 Sep 2023 15:37:48 +0300
> Matti Vaittinen <[email protected]> wrote:
>
>> Support for the ROHM BM1390 pressure sensor. The BM1390GLV-Z can measure
>> pressures ranging from 300 hPa to 1300 hPa with configurable measurement
>> averaging and internal FIFO. The sensor does also provide temperature
>> measurements.
>>
>> Sensor does also contain IIR filter implemented in HW. The data-sheet
>> says the IIR filter can be configured to be "weak", "middle" or
>> "strong". Some RMS noise figures are provided in data sheet but no
>> accurate maths for the filter configurations is provided. Hence, the IIR
>> filter configuration is not supported by this driver and the filter is
>> configured to the "middle" setting (at least not for now).
>> +
>> +static irqreturn_t bm1390_irq_thread_handler(int irq, void *private)
>> +{
>> + struct iio_dev *idev = private;
>> + struct bm1390_data *data = iio_priv(idev);
>> + int ret = IRQ_NONE;
>> +
>> + mutex_lock(&data->mutex);
>> +
>> + if (data->trigger_enabled) {
>> + iio_trigger_poll_nested(data->trig);
>> + ret = IRQ_HANDLED;
>> + }
>> +
>> + if (data->state == BM1390_STATE_FIFO) {
>
> Can this and trigger_enabled be true?
Thanks for asking this question. Intention was that these are mutually
exclusive. However, I think that the check
if (iio_device_get_current_mode(idev) == INDIO_BUFFER_TRIGGERED)
in bm1390_buffer_postenable(), before calling the bm1390_fifo_enable()
is not 100% race free.
I, however, like the idea of having this check in the buffer-enable
function - I think it makes the design much more obvious. What I will do
is adding another check for:
if (data->trigger_enable) {
ret = -EBUSY;
goto unlock_out;
}
inside the bm1390_fifo_enable() to the section which holds the mutex.
Yours,
-- Matti
--
Matti Vaittinen
Linux kernel developer at ROHM Semiconductors
Oulu Finland
~~ When things go utterly wrong vim users can always type :help! ~~
On Thu, 14 Sep 2023 14:47:44 +0300
Matti Vaittinen <[email protected]> wrote:
> On 9/10/23 16:22, Jonathan Cameron wrote:
> > On Wed, 6 Sep 2023 15:37:48 +0300
> > Matti Vaittinen <[email protected]> wrote:
> >
> >> Support for the ROHM BM1390 pressure sensor. The BM1390GLV-Z can measure
> >> pressures ranging from 300 hPa to 1300 hPa with configurable measurement
> >> averaging and internal FIFO. The sensor does also provide temperature
> >> measurements.
> >>
> >> Sensor does also contain IIR filter implemented in HW. The data-sheet
> >> says the IIR filter can be configured to be "weak", "middle" or
> >> "strong". Some RMS noise figures are provided in data sheet but no
> >> accurate maths for the filter configurations is provided. Hence, the IIR
> >> filter configuration is not supported by this driver and the filter is
> >> configured to the "middle" setting (at least not for now).
>
> >> +
> >> +static irqreturn_t bm1390_irq_thread_handler(int irq, void *private)
> >> +{
> >> + struct iio_dev *idev = private;
> >> + struct bm1390_data *data = iio_priv(idev);
> >> + int ret = IRQ_NONE;
> >> +
> >> + mutex_lock(&data->mutex);
> >> +
> >> + if (data->trigger_enabled) {
> >> + iio_trigger_poll_nested(data->trig);
> >> + ret = IRQ_HANDLED;
> >> + }
> >> +
> >> + if (data->state == BM1390_STATE_FIFO) {
> >
> > Can this and trigger_enabled be true?
>
> Thanks for asking this question. Intention was that these are mutually
> exclusive. However, I think that the check
> if (iio_device_get_current_mode(idev) == INDIO_BUFFER_TRIGGERED)
> in bm1390_buffer_postenable(), before calling the bm1390_fifo_enable()
> is not 100% race free.
>
> I, however, like the idea of having this check in the buffer-enable
> function - I think it makes the design much more obvious. What I will do
> is adding another check for:
> if (data->trigger_enable) {
> ret = -EBUSY;
> goto unlock_out;
> }
>
> inside the bm1390_fifo_enable() to the section which holds the mutex.
You could make the exclusive nature obvious in the thread_handler by using an
else if () above.
>
>
> Yours,
> -- Matti
>
>
>
On 9/17/23 12:26, Jonathan Cameron wrote:
> On Thu, 14 Sep 2023 14:47:44 +0300
> Matti Vaittinen <[email protected]> wrote:
>
>> On 9/10/23 16:22, Jonathan Cameron wrote:
>>> On Wed, 6 Sep 2023 15:37:48 +0300
>>> Matti Vaittinen <[email protected]> wrote:
>>>
>>>> Support for the ROHM BM1390 pressure sensor. The BM1390GLV-Z can measure
>>>> pressures ranging from 300 hPa to 1300 hPa with configurable measurement
>>>> averaging and internal FIFO. The sensor does also provide temperature
>>>> measurements.
>>>>
>>>> Sensor does also contain IIR filter implemented in HW. The data-sheet
>>>> says the IIR filter can be configured to be "weak", "middle" or
>>>> "strong". Some RMS noise figures are provided in data sheet but no
>>>> accurate maths for the filter configurations is provided. Hence, the IIR
>>>> filter configuration is not supported by this driver and the filter is
>>>> configured to the "middle" setting (at least not for now).
>>
>>>> +
>>>> +static irqreturn_t bm1390_irq_thread_handler(int irq, void *private)
>>>> +{
>>>> + struct iio_dev *idev = private;
>>>> + struct bm1390_data *data = iio_priv(idev);
>>>> + int ret = IRQ_NONE;
>>>> +
>>>> + mutex_lock(&data->mutex);
>>>> +
>>>> + if (data->trigger_enabled) {
>>>> + iio_trigger_poll_nested(data->trig);
>>>> + ret = IRQ_HANDLED;
>>>> + }
>>>> +
>>>> + if (data->state == BM1390_STATE_FIFO) {
>>>
>>> Can this and trigger_enabled be true?
>>
>> Thanks for asking this question. Intention was that these are mutually
>> exclusive. However, I think that the check
>> if (iio_device_get_current_mode(idev) == INDIO_BUFFER_TRIGGERED)
>> in bm1390_buffer_postenable(), before calling the bm1390_fifo_enable()
>> is not 100% race free.
>>
>> I, however, like the idea of having this check in the buffer-enable
>> function - I think it makes the design much more obvious. What I will do
>> is adding another check for:
>> if (data->trigger_enable) {
>> ret = -EBUSY;
>> goto unlock_out;
>> }
>>
>> inside the bm1390_fifo_enable() to the section which holds the mutex.
>
> You could make the exclusive nature obvious in the thread_handler by using an
> else if () above.
Right. Thanks.
>
>>
>>
>> Yours,
>> -- Matti
>>
>>
>>
>
--
Matti Vaittinen
Linux kernel developer at ROHM Semiconductors
Oulu Finland
~~ When things go utterly wrong vim users can always type :help! ~~