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    • Mark Brown's avatar
      regulator: Set PROBE_PREFER_ASYNCHRONOUS for · 02ce28bc
      Mark Brown authored 
      Merge series from Douglas Anderson <dianders@chromium.org>:

This series directly follows from the discussion when I tried to turn
on PROBE_PREFER_ASYNCHRONOUS just for the fixed-regulator [1] and
attempts to switch everything in drivers/regulator over to async
probe.

Like the similar patch series I did for the MMC subsystem a few years
ago [2], I've split this patch series into batches corresponding to
drivers corresponding to actively maintained stable kernel trees with
the idea to break the patch series up somewhat.

Most of the description of this series is contained in the first patch
of the series and then the further patches simply refer back to the
first one. The logic and reasoning behind all the patches is exactly
the same.

As talked about in the first patch, it wouldn't be at all shocking if
this broke someone. Hopefully this doesn't cause too much of a
problem. Most of the problems expected would be real underlying bugs
that already existed and were just tickled by this change. If you're
facing a problem, it's fairly easy to force individual drivers back to
"synchronous" probing while the problem is tracked down and fixed.

I am opting _not_ to CC every single person involved in each of these
regulators on this patch series because I suspect that the mailing
lists couldn't handle CCing that many people. This should be on LKML
so hopefully people can find it there and respond to it that
way. Anyone who responds will get CCed on future versions, if there
are any.

For reference, the ugly script I used is here:
  import os
  import re

  for filename in os.listdir("."):
      found_subsys = False
      found_driver = False
      output = []
      for line in open(filename, "r").readlines():
          if "struct platform_driver" in line or \
             "struct i2c_driver" in line or \
             "struct spmi_driver" in line or \
             "struct spi_driver" in line:
              found_subsys = True
          if found_subsys and re.search(r"\t\.driver\s*=\s*{", line):
              found_driver = True
              found_subsys = False
          mo = re.search(r"(\s*)\.name(\s*)=", line)
          if found_driver and mo:
              if not line.endswith(",\n"):
                  line = line[:-1] + ",\n"
              output.append(line)

              if mo.group(2) == " ":
                  space = " "
              elif mo.group(2) == "\t":
                  # Best we can do
                  space = " "
              elif mo.group(2).startswith("\t"):
                  # Guess that removing one tab is right
                  space = mo.group(2)[1:]
              else:
                  # Guess it's all spaces
                  space = mo.group(2)[7:] + " "

              output.append("%s.probe_type%s= PROBE_PREFER_ASYNCHRONOUS,\n" % (mo.group(1), space))
              found_driver = False
          else:
              output.append(line)

      open(filename, "w").write("".join(output))

I manually split drivers up into groups based on the kernel they were
introduced in.

I've run a compile test against "allyesconfig" on amd64, arm32, and
arm64 with this and confirmed it compiled. I've booted this on a
sc7180-trogdor-lazor board and confirmed it booted OK and got the boot
speed improvements I expected and that dmesg was as expected.

[1] https://lore.kernel.org/r/06db017f-e985-4434-8d1d-02ca2100cca0@sirena.org.uk
[2] https://lore.kernel.org/r/20200903232441.2694866-1-dianders@chromium.org/

Douglas Anderson (7):
  regulator: Set PROBE_PREFER_ASYNCHRONOUS for drivers that existed in
    4.14
  regulator: Set PROBE_PREFER_ASYNCHRONOUS for drivers between 4.14 and
    4.19
  regulator: Set PROBE_PREFER_ASYNCHRONOUS for drivers between 4.19 and
    5.4
  regulator: Set PROBE_PREFER_ASYNCHRONOUS for drivers between 5.4 and
    5.10
  regulator: Set PROBE_PREFER_ASYNCHRONOUS for drivers between 5.10 and
    5.15
  regulator: Set PROBE_PREFER_ASYNCHRONOUS for drivers between 5.15 and
    6.1
  regulator: Set PROBE_PREFER_ASYNCHRONOUS for drivers that are newer
    than 6.1

 drivers/regulator/88pg86x.c                    | 1 +
 drivers/regulator/88pm800-regulator.c          | 1 +
 drivers/regulator/88pm8607.c                   | 1 +
 drivers/regulator/aat2870-regulator.c          | 1 +
 drivers/regulator/ab8500-ext.c                 | 1 +
 drivers/regulator/ab8500.c                     | 1 +
 drivers/regulator/act8865-regulator.c          | 1 +
 drivers/regulator/act8945a-regulator.c         | 1 +
 drivers/regulator/ad5398.c                     | 1 +
 drivers/regulator/anatop-regulator.c           | 1 +
 drivers/regulator/arizona-ldo1.c               | 2 ++
 drivers/regulator/arizona-micsupp.c            | 2 ++
 drivers/regulator/as3711-regulator.c           | 1 +
 drivers/regulator/as3722-regulator.c           | 1 +
 drivers/regulator/atc260x-regulator.c          | 1 +
 drivers/regulator/axp20x-regulator.c           | 1 +
 drivers/regulator/bcm590xx-regulator.c         | 1 +
 drivers/regulator/bd71815-regulator.c          | 1 +
 drivers/regulator/bd71828-regulator.c          | 3 ++-
 drivers/regulator/bd718x7-regulator.c          | 1 +
 drivers/regulator/bd9571mwv-regulator.c        | 1 +
 drivers/regulator/bd9576-regulator.c           | 1 +
 drivers/regulator/cpcap-regulator.c            | 1 +
 drivers/regulator/cros-ec-regulator.c          | 1 +
 drivers/regulator/da903x-regulator.c           | 1 +
 drivers/regulator/da9052-regulator.c           | 1 +
 drivers/regulator/da9055-regulator.c           | 1 +
 drivers/regulator/da9062-regulator.c           | 1 +
 drivers/regulator/da9063-regulator.c           | 1 +
 drivers/regulator/da9121-regulator.c           | 1 +
 drivers/regulator/da9210-regulator.c           | 1 +
 drivers/regulator/da9211-regulator.c           | 1 +
 drivers/regulator/db8500-prcmu.c               | 1 +
 drivers/regulator/dummy.c                      | 1 +
 drivers/regulator/fan53555.c                   | 1 +
 drivers/regulator/fan53880.c                   | 1 +
 drivers/regulator/fixed.c                      | 1 +
 drivers/regulator/gpio-regulator.c             | 1 +
 drivers/regulator/hi6421-regulator.c           | 1 +
 drivers/regulator/hi6421v530-regulator.c       | 1 +
 drivers/regulator/hi6421v600-regulator.c       | 1 +
 drivers/regulator/hi655x-regulator.c           | 1 +
 drivers/regulator/isl6271a-regulator.c         | 1 +
 drivers/regulator/isl9305.c                    | 1 +
 drivers/regulator/lm363x-regulator.c           | 1 +
 drivers/regulator/lochnagar-regulator.c        | 1 +
 drivers/regulator/lp3971.c                     | 1 +
 drivers/regulator/lp3972.c                     | 1 +
 drivers/regulator/lp872x.c                     | 1 +
 drivers/regulator/lp873x-regulator.c           | 1 +
 drivers/regulator/lp8755.c                     | 1 +
 drivers/regulator/lp87565-regulator.c          | 1 +
 drivers/regulator/lp8788-buck.c                | 1 +
 drivers/regulator/lp8788-ldo.c                 | 2 ++
 drivers/regulator/ltc3589.c                    | 1 +
 drivers/regulator/ltc3676.c                    | 1 +
 drivers/regulator/max14577-regulator.c         | 1 +
 drivers/regulator/max1586.c                    | 1 +
 drivers/regulator/max20086-regulator.c         | 1 +
 drivers/regulator/max20411-regulator.c         | 1 +
 drivers/regulator/max597x-regulator.c          | 1 +
 drivers/regulator/max77620-regulator.c         | 1 +
 drivers/regulator/max77650-regulator.c         | 1 +
 drivers/regulator/max77686-regulator.c         | 1 +
 drivers/regulator/max77693-regulator.c         | 1 +
 drivers/regulator/max77802-regulator.c         | 1 +
 drivers/regulator/max77826-regulator.c         | 1 +
 drivers/regulator/max8649.c                    | 1 +
 drivers/regulator/max8660.c                    | 1 +
 drivers/regulator/max8893.c                    | 1 +
 drivers/regulator/max8907-regulator.c          | 1 +
 drivers/regulator/max8925-regulator.c          | 1 +
 drivers/regulator/max8952.c                    | 1 +
 drivers/regulator/max8973-regulator.c          | 1 +
 drivers/regulator/max8997-regulator.c          | 1 +
 drivers/regulator/max8998.c                    | 1 +
 drivers/regulator/mc13783-regulator.c          | 1 +
 drivers/regulator/mc13892-regulator.c          | 1 +
 drivers/regulator/mcp16502.c                   | 1 +
 drivers/regulator/mp5416.c                     | 1 +
 drivers/regulator/mp8859.c                     | 1 +
 drivers/regulator/mp886x.c                     | 1 +
 drivers/regulator/mpq7920.c                    | 1 +
 drivers/regulator/mt6311-regulator.c           | 1 +
 drivers/regulator/mt6315-regulator.c           | 1 +
 drivers/regulator/mt6323-regulator.c           | 1 +
 drivers/regulator/mt6331-regulator.c           | 1 +
 drivers/regulator/mt6332-regulator.c           | 1 +
 drivers/regulator/mt6357-regulator.c           | 1 +
 drivers/regulator/mt6358-regulator.c           | 1 +
 drivers/regulator/mt6359-regulator.c           | 1 +
 drivers/regulator/mt6360-regulator.c           | 1 +
 drivers/regulator/mt6370-regulator.c           | 1 +
 drivers/regulator/mt6380-regulator.c           | 1 +
 drivers/regulator/mt6397-regulator.c           | 1 +
 drivers/regulator/mtk-dvfsrc-regulator.c       | 1 +
 drivers/regulator/palmas-regulator.c           | 1 +
 drivers/regulator/pbias-regulator.c            | 1 +
 drivers/regulator/pca9450-regulator.c          | 1 +
 drivers/regulator/pcap-regulator.c             | 1 +
 drivers/regulator/pcf50633-regulator.c         | 1 +
 drivers/regulator/pf8x00-regulator.c           | 1 +
 drivers/regulator/pfuze100-regulator.c         | 1 +
 drivers/regulator/pv88060-regulator.c          | 1 +
 drivers/regulator/pv88080-regulator.c          | 1 +
 drivers/regulator/pv88090-regulator.c          | 1 +
 drivers/regulator/pwm-regulator.c              | 1 +
 drivers/regulator/qcom-labibb-regulator.c      | 1 +
 drivers/regulator/qcom-rpmh-regulator.c        | 1 +
 drivers/regulator/qcom_rpm-regulator.c         | 1 +
 drivers/regulator/qcom_smd-regulator.c         | 1 +
 drivers/regulator/qcom_spmi-regulator.c        | 1 +
 drivers/regulator/qcom_usb_vbus-regulator.c    | 1 +
 drivers/regulator/rc5t583-regulator.c          | 1 +
 drivers/regulator/rk808-regulator.c            | 3 ++-
 drivers/regulator/rn5t618-regulator.c          | 1 +
 drivers/regulator/rpi-panel-attiny-regulator.c | 1 +
 drivers/regulator/rt4801-regulator.c           | 1 +
 drivers/regulator/rt4831-regulator.c           | 1 +
 drivers/regulator/rt5033-regulator.c           | 1 +
 drivers/regulator/rt5120-regulator.c           | 1 +
 drivers/regulator/rt5190a-regulator.c          | 1 +
 drivers/regulator/rt5739.c                     | 1 +
 drivers/regulator/rt5759-regulator.c           | 1 +
 drivers/regulator/rt6160-regulator.c           | 1 +
 drivers/regulator/rt6190-regulator.c           | 1 +
 drivers/regulator/rt6245-regulator.c           | 1 +
 drivers/regulator/rtmv20-regulator.c           | 1 +
 drivers/regulator/rtq2134-regulator.c          | 1 +
 drivers/regulator/rtq6752-regulator.c          | 1 +
 drivers/regulator/s2mpa01.c                    | 1 +
 drivers/regulator/s2mps11.c                    | 1 +
 drivers/regulator/s5m8767.c                    | 1 +
 drivers/regulator/sc2731-regulator.c           | 1 +
 drivers/regulator/sky81452-regulator.c         | 1 +
 drivers/regulator/slg51000-regulator.c         | 1 +
 drivers/regulator/sm5703-regulator.c           | 1 +
 drivers/regulator/stm32-booster.c              | 1 +
 drivers/regulator/stm32-pwr.c                  | 1 +
 drivers/regulator/stm32-vrefbuf.c              | 1 +
 drivers/regulator/stpmic1_regulator.c          | 1 +
 drivers/regulator/stw481x-vmmc.c               | 1 +
 drivers/regulator/sy7636a-regulator.c          | 1 +
 drivers/regulator/sy8106a-regulator.c          | 1 +
 drivers/regulator/sy8824x.c                    | 1 +
 drivers/regulator/sy8827n.c                    | 1 +
 drivers/regulator/ti-abb-regulator.c           | 1 +
 drivers/regulator/tps51632-regulator.c         | 1 +
 drivers/regulator/tps6105x-regulator.c         | 1 +
 drivers/regulator/tps62360-regulator.c         | 1 +
 drivers/regulator/tps6286x-regulator.c         | 1 +
 drivers/regulator/tps65023-regulator.c         | 1 +
 drivers/regulator/tps6507x-regulator.c         | 1 +
 drivers/regulator/tps65086-regulator.c         | 1 +
 drivers/regulator/tps65090-regulator.c         | 1 +
 drivers/regulator/tps65132-regulator.c         | 1 +
 drivers/regulator/tps65217-regulator.c         | 1 +
 drivers/regulator/tps65218-regulator.c         | 1 +
 drivers/regulator/tps65219-regulator.c         | 1 +
 drivers/regulator/tps6524x-regulator.c         | 1 +
 drivers/regulator/tps6586x-regulator.c         | 1 +
 drivers/regulator/tps65910-regulator.c         | 1 +
 drivers/regulator/tps65912-regulator.c         | 1 +
 drivers/regulator/tps68470-regulator.c         | 1 +
 drivers/regulator/twl-regulator.c              | 1 +
 drivers/regulator/twl6030-regulator.c          | 1 +
 drivers/regulator/uniphier-regulator.c         | 1 +
 drivers/regulator/userspace-consumer.c         | 1 +
 drivers/regulator/vctrl-regulator.c            | 1 +
 drivers/regulator/vexpress-regulator.c         | 1 +
 drivers/regulator/virtual.c                    | 1 +
 drivers/regulator/vqmmc-ipq4019-regulator.c    | 1 +
 drivers/regulator/wm831x-dcdc.c                | 4 ++++
 drivers/regulator/wm831x-isink.c               | 1 +
 drivers/regulator/wm831x-ldo.c                 | 3 +++
 drivers/regulator/wm8350-regulator.c           | 1 +
 drivers/regulator/wm8400-regulator.c           | 1 +
 drivers/regulator/wm8994-regulator.c           | 1 +
 178 files changed, 188 insertions(+), 2 deletions(-)

--
2.40.0.rc1.284.g88254d51c5-goog
      02ce28bc
  13. Mar 20, 2023
  15. Mar 14, 2023
    • Douglas Anderson's avatar
      regulator: core: Shorten off-on-delay-us for always-on/boot-on by time since booted · 691c1fcd
      Douglas Anderson authored 
      This is very close to a straight revert of commit 218320fe
("regulator: core: Fix off-on-delay-us for always-on/boot-on
regulators"). We've identified that patch as causing a boot speed
regression on sc7180-trogdor boards. While boot speed certainly isn't
more important than making sure that power sequencing is correct,
looking closely at the original change it doesn't seem to have been
fully justified. It mentions "cycling issues" without describing
exactly what the issues were. That means it's possible that the
cycling issues were really a problem that should be fixed in a
different way.

Let's take a careful look at how we should handle regulators that have
an off-on-delay and that are boot-on or always-on. Linux currently
doesn't have any way to identify whether a GPIO regulator was already
on when the kernel booted. That means that when the kernel boots we
probe a regulator, see that it wants boot-on / always-on we, and then
turn the regulator on. We could be in one of two cases when we do
this:

a) The regulator might have been left on by the bootloader and we're
   ensuring that it stays on.
b) The regulator might have been left off by the bootloader and we're
   just now turning it on.

For case a) we definitely don't need any sort of delay. For case b) we
_might_ need some delay in case the bootloader turned the regulator
off _right_ before booting the kernel. To get the proper delay for
case b) then we can just assume a `last_off` of 0, which is what it
gets initialized to by default.

As per above, we can't tell whether we're in case a) or case b) so
we'll assume the longer delay (case b). This basically puts the code
to how it was before commit 218320fe ("regulator: core: Fix
off-on-delay-us for always-on/boot-on regulators"). However, we add
one important change: we make sure that the delay is actually honored
if `last_off` is 0. Though the original "cycling issues" cited were
vague, I'm hopeful that this important extra change will be enough to
fix the issues that the initial commit mentioned.

With this fix, I've confined that on a sc7180-trogdor board the delay
at boot goes down from 500 ms to ~250 ms. That's not as good as the 0
ms that we had prior to commit 218320fe ("regulator: core: Fix
off-on-delay-us for always-on/boot-on regulators"), but it's probably
safer because we don't know if the bootloader turned the regulator off
right before booting.

One note is that it's possible that we could be in a state that's not
a) or b) if there are other issues in the kernel. The only one I can
think of is related to pinctrl. If the pinctrl driver being used on a
board isn't careful about avoiding glitches when setting up a pin then
it's possible that setting up a pin could cause the regulator to "turn
off" briefly immediately before the regulator probes. If this is
indeed causing problems then the pinctrl driver should be fixed,
perhaps in a similar way to what was done in commit d21f4b7f
("pinctrl: qcom: Avoid glitching lines when we first mux to output")

Fixes: 218320fe

 ("regulator: core: Fix off-on-delay-us for always-on/boot-on regulators")
Cc: Christian Kohlschütter <christian@kohlschutter.com>
Signed-off-by: default avatarDouglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20230313111806.1.I2eaad872be0932a805c239a7c7a102233fb0b03b@changeid


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
      691c1fcd
  17. Mar 13, 2023
  19. Mar 12, 2023
  21. Mar 11, 2023