Hi Andy,
On Wed, Apr 27, 2022 at 6:04 PM Andy Shevchenko
<andy.shevchenko@xxxxxxxxx> wrote:
>
> On Wed, Apr 20, 2022 at 11:11 PM Jagath Jog J <jagathjog1996@xxxxxxxxx> wrote:
> >
> > Added channel for step counter which can be enable or disable
> > through the sysfs interface.
>
> ...
>
> > +static int bma400_enable_steps(struct bma400_data *data, int val)
> > +{
> > + int ret;
> > +
> > + if (data->steps_enabled == val)
> > + return 0;
> > +
> > + ret = regmap_update_bits(data->regmap, BMA400_INT_CONFIG1_REG,
> > + BMA400_STEP_INT_MSK,
> > + FIELD_PREP(BMA400_STEP_INT_MSK, !!val));
>
> > + data->steps_enabled = val;
>
> This will update the value even if we got an error and actual device
> state is unknown here. Does this make sense?
I will correct this in the next series.
>
> > + return ret;
> > +}
>
> ...
>
> I perhaps missed why kmalloc() is needed now. Any pointers to the discussion?
Here step is a 24-bit value and since this is a sysfs channel read (slow path),
kmalloc() is used to make the buffer DMA safe to read the multibyte value
using regmap_bulk_read().
>
> --
> With Best Regards,
> Andy Shevchenko
Thank you,
Jagath
