> > LSM9DS1 does not support hw FIFO for the moment. Are you trying to enable
> > buffered reading?
> 
> I am not manually interacting with the device at all when this
> exception occurs. This happens during the driver probe.
> 
> > Could you please try if the following patch helps? (just compiled)
> 
> I no longer receive the exception with this patch and it makes sense, thanks.

Hi Bobby,

thx a lot for testing. Could you please try to drop the previous patch and
apply the following one? Does it fix the issue as well?

iio: imu: st_lsm6dsx: check read_fifo pointer in st_lsm6dsx_handler_thread

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
---
 drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c
index b0f3da1976e4..f4fd4842bd79 100644
--- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c
+++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c
@@ -666,6 +666,9 @@ static irqreturn_t st_lsm6dsx_handler_thread(int irq, void *private)
 	struct st_lsm6dsx_hw *hw = private;
 	int count;
 
+	if (!hw->settings->fifo_ops.read_fifo)
+		return IRQ_NONE;
+
 	mutex_lock(&hw->fifo_lock);
 	count = hw->settings->fifo_ops.read_fifo(hw);
 	mutex_unlock(&hw->fifo_lock);
-- 
2.21.0

> 
> For context I'm working with a board that has every data ready and
> interrupt signal connected to the LSM9DS1. Could you clarify what the
> proper usage of the "st,drdy-int-pin" would be in this case and
> whether or not I need more than one interrupt called out in my device
> tree node?
> I'm not really understanding how they're currently being utilized for
> this device in the driver.

For the moment irq line in lsm9ds1 (acc/gyro) is not used at all,
so you can omit the "st,drdy-int-pin" property

> 
> Also, I know support for this device was added recently and the combo
> device hardware FIFO is complex, but is support for this something
> that's currently being worked on?

It is actually in my ToDo list but I have no this device at the moment, so
patches are welcome :)

Regards,
Lorenzo

> 
> Thanks,
> Bobby Jones
> 
> > Regards,
> > Lorenzo
> >
> > iio: imu: st_lsm6dsx: do not configure the fifo if not supported
> >
> > Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
> > ---
> >  drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c
> > index b65a6ca775e0..90a0e5ce44e5 100644
> > --- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c
> > +++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c
> > @@ -1572,7 +1572,7 @@ int st_lsm6dsx_probe(struct device *dev, int irq, int hw_id,
> >                         return err;
> >         }
> >
> > -       if (hw->irq > 0) {
> > +       if (hw->irq > 0 && hw->settings->fifo_ops.update_fifo) {
> >                 err = st_lsm6dsx_fifo_setup(hw);
> >                 if (err < 0)
> >                         return err;
> > --
> > 2.21.0
> >
> >