On Sun, 2018-05-06 at 17:19 +0100, Jonathan Cameron wrote: > On Mon, 30 Apr 2018 12:25:46 +0800 > Shrirang Bagul <shrirang.ba...@canonical.com> wrote: > > > CTRL1 register (ODR & BDU settings) gets reset after system comes back > > from suspend, causing subsequent reads from the sensor to fail. > > > > This patch restores the CTRL1 register after resume. > > > > Based on: > > git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio.git > > iio-fixes-for-4.14b > > > > Since 4.17.rc1, this driver uses REGMAP; I'll send a separate patch to > > address this issue. > > > > Cc: sta...@vger.kernel.org > > Fixes: ffebe74b7c95 (iio: humidity: hts221: avoid useless ODR > > reconfiguration) > > Looks like part of the problem was introduced in that patch, part well > predated > it (BDU). > > > Signed-off-by: Shrirang Bagul <shrirang.ba...@canonical.com> > > As you way, this needs to be a bit different to take into account > the change to regmap. We'll need to have that upstream before we look > at a back port. One element inline surprises me and needs further > explanation. I have sent a patch based on iio-for-4.17b [1], Lorenzo and I are still discussing our findings. It's not just the CTRL1 reg, but also the AV_CONF(0x10) reg. which loses it's contents coming out of suspend.
[1] https://marc.info/?l=linux-iio&m=152534455701742&w=2 > > > > --- > > drivers/iio/humidity/hts221_core.c | 12 ++++++++---- > > 1 file changed, 8 insertions(+), 4 deletions(-) > > > > diff --git a/drivers/iio/humidity/hts221_core.c > > b/drivers/iio/humidity/hts221_core.c > > index 32524a8dc66f..fed2da64fa3b 100644 > > --- a/drivers/iio/humidity/hts221_core.c > > +++ b/drivers/iio/humidity/hts221_core.c > > @@ -674,11 +674,15 @@ static int __maybe_unused hts221_resume(struct device > > *dev) > > struct hts221_hw *hw = iio_priv(iio_dev); > > int err = 0; > > > > - if (hw->enabled) > > - err = hts221_write_with_mask(hw, HTS221_REG_CNTRL1_ADDR, > > - HTS221_ENABLE_MASK, true); > > Why drop the enable setting? Seems that we want to do this 'as well', > if the device was previous enabled. Yes, will cover this in v2. > > > + err = hts221_write_with_mask(hw, HTS221_REG_CNTRL1_ADDR, > > + HTS221_BDU_MASK, 1); > > + if (err < 0) > > + goto fail_err; > > > > - return err; > > + err = hts221_update_odr(hw, hw->odr); > > + > > +fail_err: > > + return err < 0 ? err : 0; > > } > > > > const struct dev_pm_ops hts221_pm_ops = { > >
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