Re: [PATCH] iio: imu: st_lsm6dsx: flush hw FIFO before resetting the device

[Jonathan Cameron <jic23@kernel.org>]

On Sat, 4 Apr 2020 19:09:18 +0200
Lorenzo Bianconi <lorenzo.bianconi@redhat.com> wrote:

> >
> > On Sat, 4 Apr 2020 18:29:25 +0200
> > Lorenzo Bianconi <lorenzo.bianconi@redhat.com> wrote:
> >  
> > > >
> > > > Hi Lorenzo,
> > > >
> > > > From: Lorenzo Bianconi <lorenzo@kernel.org>
> > > > Date: Fri, Mar 13, 2020 at 18:06:00
> > > >  
> > > > > flush hw FIFO before device reset in order to avoid possible races
> > > > > on interrupt line 1. If the first interrupt line is asserted during
> > > > > hw reset the device will work in I3C-only mode (if it is supported)
> > > > >  
> > >
> > > Hi Jonathan,
> > >
> > > any news about this patch? Maybe I am wrong but I am not able to find
> > > it in your tree.
> > > Thanks in advance.  
> >
> > I'm running a bit behind on catching up with fixes after it became obvious
> > they wouldn't make the merge window.
> >
> > Applied to the fixes-togreg branch of iio.git and marked for stable.
> >  
> 
> ack, thx...sorry for all the noise around it.

No problem - it reminded me to actually do something about this and other
patches in the same position ;)

Jonathan
> 
> Regards,
> Lorenzo
> 
> > >
> > > Regards,
> > > Lorenzo
> > >
> > >  
> > > > > Fixes: 801a6e0af0c6 ("iio: imu: st_lsm6dsx: add support to LSM6DSO")
> > > > > Fixes: 43901008fde0 ("iio: imu: st_lsm6dsx: add support to LSM6DSR")
> > > > > Reported-by: Mario Tesi <mario.tesi@st.com>
> > > > > Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
> > > > > ---
> > > > > This is a new version of: "iio: imu: st_lsm6dsx: disable I3C support during
> > > > > device reset"
> > > > > https://urldefense.proofpoint.com/v2/url?u=https-3A__patchwork.kernel.org_patch_11425389_&d=DwIDAg&c=DPL6_X_6JkXFx7AXWqB0tg&r=qVuU64u9x77Y0Kd0PhDK_lpxFgg6PK9PateHwjb_DY0&m=d7oUzE4fWeY3JqYqqd-uW_v1SJkij_sOpXRvpm3-Thg&s=BEgROrIZoG9oGrwQEENFz0DP88VioXUhpeZP2Y168XI&e=
> > > > > ---
> > > > >  drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c | 24 +++++++++++++++++++-
> > > > >  1 file changed, 23 insertions(+), 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 84d219ae6aee..4426524b59f2 100644
> > > > > --- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c
> > > > > +++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c
> > > > > @@ -2036,11 +2036,21 @@ static int st_lsm6dsx_init_hw_timer(struct st_lsm6dsx_hw *hw)
> > > > >       return 0;
> > > > >  }
> > > > >
> > > > > -static int st_lsm6dsx_init_device(struct st_lsm6dsx_hw *hw)
> > > > > +static int st_lsm6dsx_reset_device(struct st_lsm6dsx_hw *hw)
> > > > >  {
> > > > >       const struct st_lsm6dsx_reg *reg;
> > > > >       int err;
> > > > >
> > > > > +     /*
> > > > > +      * flush hw FIFO before device reset in order to avoid
> > > > > +      * possible races on interrupt line 1. If the first interrupt
> > > > > +      * line is asserted during hw reset the device will work in
> > > > > +      * I3C-only mode (if it is supported)
> > > > > +      */
> > > > > +     err = st_lsm6dsx_flush_fifo(hw);
> > > > > +     if (err < 0 && err != -ENOTSUPP)
> > > > > +             return err;
> > > > > +
> > > > >       /* device sw reset */
> > > > >       reg = &hw->settings->reset;
> > > > >       err = regmap_update_bits(hw->regmap, reg->addr, reg->mask,
> > > > > @@ -2059,6 +2069,18 @@ static int st_lsm6dsx_init_device(struct st_lsm6dsx_hw *hw)
> > > > >
> > > > >       msleep(50);
> > > > >
> > > > > +     return 0;
> > > > > +}
> > > > > +
> > > > > +static int st_lsm6dsx_init_device(struct st_lsm6dsx_hw *hw)
> > > > > +{
> > > > > +     const struct st_lsm6dsx_reg *reg;
> > > > > +     int err;
> > > > > +
> > > > > +     err = st_lsm6dsx_reset_device(hw);
> > > > > +     if (err < 0)
> > > > > +             return err;
> > > > > +
> > > > >       /* enable Block Data Update */
> > > > >       reg = &hw->settings->bdu;
> > > > >       err = regmap_update_bits(hw->regmap, reg->addr, reg->mask,
> > > > > --
> > > > > 2.24.1  
> > > >
> > > > I tested the patch and the I3C interface is working fine in this version.
> > > >
> > > > Reviewed-by: Vitor Soares <vitor.soares@synopsys.com>
> > > > Tested-by: Vitor Soares <vitor.soares@synopsys.com>
> > > >  
> >  
> > > > Best regards,
> > > > Vitor
> > > > Soares
> > > >
> > > >  
> > >  
> >  
>