[PATCH v4 0/6] driver core: Try to improve and cleanup driver_deferred_probe_check_state()

From: John Stultz
Date: Thu Feb 20 2020 - 00:04:47 EST

This series tries to improve and cleanup the
driver_deferred_probe_check_state() code in the driver core.

This is most important for being able to support modules
dependencies which may be loaded by userland, far after
late_initcall is done. For instance, this series allows
us to use successfully various clk drivers as modules on
the db845c board. And without it, those drivers have to
be statically built in to work.

The first patch (or two) is really the most critical for me,
but as I was working to understand the code (and with some
prodding), it seemed a further cleanup was in order.

If folks have concerns about the tail end of the patch set, I'm
fine to defer that. The main issue for me is the inability to
load module dependencies after init starts.

New in v4:
* Split earlier version of the patches apart
* Defaulting deferred_probe_timeout to 30 seconds if modules
are enabled.
* Deeper cleanup on driver_deferred_probe_check_state_continue()

Feedback would be greatly appreciated!


Cc: Rob Herring <robh@xxxxxxxxxx>
Cc: "Rafael J. Wysocki" <rjw@xxxxxxxxxxxxx>
Cc: Kevin Hilman <khilman@xxxxxxxxxx>
Cc: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Cc: Pavel Machek <pavel@xxxxxx>
Cc: Len Brown <len.brown@xxxxxxxxx>
Cc: Todd Kjos <tkjos@xxxxxxxxxx>
Cc: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
Cc: Liam Girdwood <lgirdwood@xxxxxxxxx>
Cc: Mark Brown <broonie@xxxxxxxxxx>
Cc: Thierry Reding <treding@xxxxxxxxxx>
Cc: Linus Walleij <linus.walleij@xxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: linux-pm@xxxxxxxxxxxxxxx

John Stultz (6):
driver core: Fix driver_deferred_probe_check_state() logic
driver core: Set deferred_probe_timeout to a longer default if
pinctrl: Remove use of driver_deferred_probe_check_state_continue()
driver core: Remove driver_deferred_probe_check_state_continue()
driver core: Rename deferred_probe_timeout and make it global
regulator: Use driver_deferred_probe_timeout for

drivers/base/dd.c | 78 ++++++++++++-----------------------
drivers/pinctrl/devicetree.c | 9 ++--
drivers/regulator/core.c | 25 ++++++-----
include/linux/device/driver.h | 2 +-
4 files changed, 47 insertions(+), 67 deletions(-)