On Wed, 19 Nov 2014 23:37:41 +0100 Hartmut Knaack <knaac...@gmx.de> wrote:
> NeilBrown schrieb am 08.11.2014 01:18:
> >
> >
> > Unless we put the device to sleep when not it use, it wastes
> > 6mA.
> >
> > If the device is asleep on probe, the 'id' register
> > sometimes mis-reads - so reset first. If the device responds
> > at all a command sent to the address, it is almost certainly
> > the correct device already.
> >
> Hi Neil,
> I still have some question and issues, see inline.
> > Signed-off-by: NeilBrown <n...@brown.name>
> >
> > diff --git a/drivers/iio/gyro/itg3200_core.c
> > b/drivers/iio/gyro/itg3200_core.c
> > index 6a8020d48140..394667fb23f9 100644
> > --- a/drivers/iio/gyro/itg3200_core.c
> > +++ b/drivers/iio/gyro/itg3200_core.c
> > @@ -223,6 +223,7 @@ static int itg3200_initial_setup(struct iio_dev
> > *indio_dev)
> > int ret;
> > u8 val;
> >
> > + ret = itg3200_reset(indio_dev);
> You should check possible error codes here. Also, there is still another
> reset issued some lines further down, although in between, there is only the
> register-read performed, which we see right below here - I would assume this
> wouldn't change anything in the device to require another reset. So, in
> conclusion, wouldn't it be sufficient to just move the reset part from
> further down up here?
> > ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_ADDRESS, &val);
> > if (ret)
> > goto err_ret;
> > @@ -351,6 +352,35 @@ static int itg3200_remove(struct i2c_client *client)
> > return 0;
> > }
> >
> > +#ifdef CONFIG_PM_SLEEP
> > +static int itg3200_suspend(struct device *dev)
> > +{
> > + struct iio_dev *indio_dev = dev_get_drvdata(dev);
> > + struct itg3200 *st = iio_priv(indio_dev);
> > + int ret;
> > +
> > + dev_dbg(&st->i2c->dev, "suspend device");
> > +
> > + ret = itg3200_write_reg_8(indio_dev,
> > + ITG3200_REG_POWER_MANAGEMENT,
> > + ITG3200_SLEEP);
> > + return ret;
> No need for ret, if you do it like this (fixing also some indentation issue):
> return itg3200_write_reg_8(indio_dev, ITG3200_REG_POWER_MANAGEMENT,
> ITG3200_SLEEP);
hi Hartmut,
thanks for these suggestions. I made the changes you suggested to my code,
but it appears that I never replied or reposted. Sorry about that.
I'll resubmit in a moment...
Thanks,
NeilBrown
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